There is considerable room for consolidation in the ETL tools market. There was a similar situation with Client-Server front-ends in the early 1990's. Of the 20 or so front-ends back then, only two remain today (Powerbuilder and Progress) while Visual Basic emerged from nowhere to be extremely competitive.
The same thing is or will be happening with ETL tools. As I mentioned earlier in this thread, Microsoft is going after the market leader, Informatica, with Yukon, the next version of DTS (Data Transformation Services). From what I have seen and heard, this new version of DTS will be a considerable technical advancement, and with the price of DTS being reasonable (the cost of SQL Server database and client licenses = say, about $30k), Informatica, Data Stage, and all those other ETL tools will be forced to cut pricing or lose market share.
When Microsoft has made up its mind to enter a particular market, it invariably gets considerable market share. Witness Windows CE versus Palm OS - Palm is a much smaller and better OS, but Microsoft has market share. Remember Netscape Navigator and what Microsoft did to it with Internet Explorer. The same thing is going to happen with Microsoft DTS and the rest of the ETL tool world. The tool you pick today could well be obsolete in 5-7 years. If that is not a concern for you, so be it. If you are worried about the obsolescence of your ETL tool, unless you are with Informatica already,I would go with Microsoft DTS now. Stay away from the niche products such as those offered by BO, Cognos, SAS, Harte-Hanks, etc.
Mark my words. In ten years, the only major players in the ETL tool space will be Microsoft, Informatica (or the company that buys them), Data Stage (or the company that buys them), and perhaps one or two others "sleepers" such as ab Initio.
Sometimes the grass is greener on the other side because there is more manure there - original.