This is a tough call because there are several clear (to me anyway) obstacles. The CME listing a few years ago ignited a mania in public exchanges. (I don't say bubble because if they all meltdown it would not have a ghastly effect on all US capital markets the way tech did.)
Also the NYSE has not been a global leader in getting new types of products on its exchange. While I concede this may be beyond their control, the fact is the NYSE was not first with a gold ETF, was not first with an oil ETF and there are other markets not easily accessed through NYSE listings.
If you buy into the idea of investment products becoming an area for innovation and more sophistication, we may see more exotic products elsewhere. Also, if hedge funds continue to become more prevalent, they might demand more futures-based products, not domestic equities. The cost of Sarbox is causing some ADRs to delist like Australian retailer Coles Myer.
A more interesting public exchange might be the London Stock exchange, which you can trade in the states under ticker LDNXF. In addition to beating the NYSE to market with gold and oil ETFs, they also list closed-end funds that access Egypt and Vietnam. You may not want to own Egypt or Vietnam but the idea is more innovative products not what you personally would buy.