Currently PC gaming is in a good place. If you bought a high end gaming pc 2 years ago it's probably still well above recommended specs. Mostly because the hardware race has slowed cause the difference in new tech and old tech isn't really that dramatic of a change when it comes to gaming. This might be due to the economic climate, or just a natural order of things, but it's really helped out consumers who've been trying to keep up w/ the Jones' (AMD, intel, Nvidia, and ATI). Their hardware arms race is one of a few reasons PC gaming has driven away consumers, and developers.
Piracy is a serious issue for developers in this global tech age. While many tend to blow it out of proportion it's still something you have to consider when releasing on any platform not just pc. The DS, and PSP are two other examples of platforms where piracy seems to be a serious issue. On PC piracy is a problem because often the pirated versions of games are cheaper, easier to obtain, and easier to run. Imagine you're 15 years old and want a copy of Bioshock 2 for PC. First off you can't order it from an online retailer like steam since you don't have a credit card, some stores probably have it in stock, but you're 15 so you'll have to ride your, bike or take the bus. If you happen to get it, and it doesn't work on your PC you can't return it. You'll have to figure out the DRM, and if you have the knowledge to fix a problem with DRM you already have more than enough knowledge to get a pirated version which is not going to have any DRM requirements. Who can really blame consumers when piracy meets all their needs, and legit buyers are left in the cold. Steam might be an answer to that. While it's not cheaper than piracy it is much easier to get games on steam, and easier to run steam games than pirated ones. Consumers have repeatedly shown they will pay more when convenient so it's possible to compete with free especially with the shady pirate community, and the amount of personal information people keep on their pcs.
Today's game industry isn't lacking for ideas so if you're selling an idea then you're out of luck. If you have marketing experience, and can persuade a publisher that this type of game would make them money it's not a bad path, but I'm sure publishers hear the "I've got a game idea that will make you millions" pitch so often they just ignore it. If you really want to pursue it I suggest visiting GDC, and talking with people. Publishers, developers, gamers, press, indie developers will all give you a perspective of what direction to head w/ your idea. You'll probably get farther asking for advice than you would trying to make a pitch at this point.
Now w/ the recent price cut on the ps3 slim Sony is knowingly losing money on the ps3. The ps3 is selling better, and will probably continue to sell well assuming it makes another price cut, and the ps3 continues to release great software.
The Wii however is seeing a decline in sales, and it's not surprising. It's pretty much hit full saturation, and w/out re-releasing a new variation of the console Wii sales will continue to drop.