James Mishler has a blog post on the economics of RPG publishing which does make for grim reading in many ways. Funnily enough I think that pen and paper RPG could grow in popularity due to the recession as the cost per hour of gaming is low if just a set of rules and dice need to be bought, but it is tough for publishers as the price that their products will sell it is low and unlikely to grow. I suspect that most publishing will become pdf only with consumers needing to get their own copies printed rather than any rebirth of print products.
The companies that I do see surviving, apart from Wizards of the Coast with its big corporate parent of Hasbro, are Mongoose Publishing, the Chaosium, Fantasy Flight Games, Steve Jackson Games, White Wolf and Goodman games. I don't claim any special insight, but these are all larger established companies many with diversified product ranges that will help support their RPG publishing activities by sharing of corporate costs like accounting, offices, warehousing and advertising. There will undoubtedly be others but without knowing information that many companies tend to keep under their hat it would be difficult to predict.
It is true to say that the success of D&D in the early 1980s was due to a combination of factors that are not that likely to reoccur with less competition for leisure time as computer games were a small niche then compared to the current widespread of games consoles like the X-Box, Wii and PlayStation and higher disposable incomes than the current period even though the economy did have a rocky patch in the early 1980s. For any roleplayer or wargamer for that matter the main aims would have to be keep recruiting new players so that the hobby survives in some form even if the industry side of it reverts to the cottage industry model that existed in the mid 1970s.