The ETF industry has expanded by leaps and bounds in recent years, with new issuers entering the arena and countless new product launches that offer investors the ability to gain exposure to various geographic regions and investment styles. The first ETFs were essentially plain vanilla products that mirrored widely-followed equity benchmarks. Today, the vast majority of ETF assets is still invested in these more traditional funds, but numerous more exotic products are gaining in popularity. Enhanced index ETFs. actively-managed ETFs. long/short ETFs, and leveraged ETFs are just a few of the innovations that have been embraced by investors.

Some contend that the ETF industry is nearing a saturation point, noting that dozens of funds have struggled to attract a sufficient asset base and could be in danger of closing. We think quite the opposite. Although investor demand is difficult to predict, heres a look at ten ETF strategies wed like to see hit the market (sign up for our Free ETF Newsletter to see if any of these ETFs ever make it to market):

1. Targeted Corporate Bond ETFs

Despite the importance of the fixed income asset class in a well-diversified, long-term portfolio, the fixed income ETF options are relatively limited, particularly for investors looking to gain exposure beyond Treasuries. According to our Free ETF Screener. there are only about 75 fixed income ETFs available, compared to more than 600 equity funds. And most of the existing ETF products have significant allocations to Treasuries and U.S. agency securities, which makes them less appealing for investors interested in following a Ben Graham-esque investment strategy.

LQD offers diversified exposure to the corporate bond market, but its essentially the only product covering this area. More targeted corporate bond ETFs (by industry, duration, credit quality, etc.) would likely be a huge hit with investors.

2. Poland ETF

Poland is the worlds 18th largest economy by GDP, but there is no ETF devoted exclusively to the Polish equity markets. ETFs focusing on Thailand (#35 on the list of largest economies), Israel (#42), and Peru (#55) are all available to U.S. investors, but exposure to the Warsaw Stock Exchange is hard to come by.

Poland is a shining example of a country that successfully transitioned from a centrally-planned economy to a capitalist market-based economy, thanks in large part to aggressive policies implemented since the fall of communism. Poland has a large agricultural sector, and if the nation becomes more closely aligned with the rest of Europe (Poland was scheduled to enter the euro zone in 2012, but that date was recently canceled ), it could become the primary food supplier to the EU.

Poland faces many obstacles, including high unemployment and net outflows of workers, but offers some intriguing investment opportunities as well.

3. Alternative Inflation-Protected ETF

As worries about the intermediate to long-term impacts of the massive stimulus plans proliferate, inflation-protected bond ETFs have become an increasingly important risk reduction tool in many investor portfolios. But there are some drawbacks of investments in TIPS. Since principal amounts are based on CPI as reported by the government, if these figures are manipulated or under-reported (as many believe they are ), returns offered by these products may be subject to inflation erosion after all.

Wed love to see an inflation-protected ETF (or, more likely, an ETN) that independently measures and reports price increases and decreases (using a transparent methodology). Such a product should put the minds of conspiracy-theorists at ease, and appeal to black swan investors .

4. Egypt ETF

The geographic reach of exchange-traded products has expanded significantly in recent years, but coverage of Africa remains rather thin. While there are ETFs offering diversified exposure to Africa (Van Ecks AFK ), country-specific exposure is limited to South Africa (through iShares EZA ). As investors regain their appetite for risk, new emerging and frontier market investment opportunities may garner some interest [see more holdings of AFK here ].

Egypts economy is led by the service sector, including tourism, trade, and banking. Given its proximity to the Suez Canal, shipping services are also a major component of the economy. Investments in Egypt are obviously risky trade deficits, high inflation, and heavy government regulations are just a few barriers to over come but the country offers a unique opportunity for investors looking to gain exposure to Africa .

This ETF may become a reality at some point in the near future, as Global X filed for approval [PDF] of the Global X FTSE Egypt 30 ETF with the SEC late last year.

5. Bill Gross Actively-Managed Bond ETF

Pimco recently completed the successful launches of two fixed income ETFs, and has already established itself as a major player in the space. The Newport Beach, California-based firm is the worlds largest bond fund manager thanks in part to the stellar track record of co-founder Bill Gross.

Actively-managed equity ETFs have already hit the market, and many anticipate that Pimco will soon jump into the actively-managed bond ETF game (PowerShares has already pioneered this space, launching the first actively-managed bond ETF, PLK. in April 2008). If Pimco does launch a product that combines Gross proven investment strategies with the benefits of the exchange-traded structure, it will surely be a hit among investors.

6. Ultra-Risky, Ultra-Aggressive ETF

ETFs that diversify across multiple asset classes are nothing new. iShares offers an aggressive allocation ETF (in addition to conservative and moderate allocation funds), but AOA is heavy in large and mid cap domestic equities, which fall somewhere in the middle of the investment universe risk continuum [see more information on AOA’s fact sheet ].

Its time for an ETF that takes aggressive asset allocation to the extreme. So how about an ultra-aggressive allocation ETF that maintains equity exposure through small-caps and emerging markets and fixed income exposure from emerging markets bond funds? I imagine an ETF of ETFs that looks something like this: