Wedbush Morgan Securities analyst Michael Pachter is a mainstay in video game journalism, and his recent report is well worth your attention.
As summarized by Joystiq , Pachter's massive 200+ page report talks about the future of the industry; specifically, the longevity of the current console life cycle. In this report of novel proportions, he not only pointed out the very real possibility of a WiiHD, but said this generation of consoles will be the longest in history due to HD displays and console SKUs. Pachter indicates the small adoption rates for HD displays and says that unless this changes, the longevity of the consoles currently on the market will expand. Further, if you consider the fact that it costs developers and publishers more than ever to be a part of the industry, you can expect a very long console cycle. In fact, Pachter believes you won't even see console sales hit their peak until "early next decade" (which is next year, of course). In addition, as costs are high and manufacturers are continually looking for ways to make things easier on consumers, multiple SKUs will come into play, as we've seen already. Pachter does mention the feasibility of the PS3 Slim and the upcoming bundles for the Xbox 360, and we can probably expect even more SKUs to come our way in the coming years.
Essentially, this report flies directly in the face of any rumors you may have heard that new consoles will be on sale within the next few years. It just seems very unlikely, according to this analyst.