I know that pretty much everyone's heard about the Revolution controller, but something that I find really interesting about the new system is the "Virtual Console." The idea is to make Nintendo's entire library downloadable from NES-N64 (the system will simply play GameCube disks) as well as possible new indie games. Sega is talking about having Master System and Genesis content on as virtual consoles (I hear there are a lot of good Dreamcast RPGs, so it'd be great to see them on there too) and Nintendo states that the "usual suspects" will likely have their old games on too (Capcom, Konami, etc???).
While most of us can simply download old games to our computers, I still find this really appealing. I'd very much perfer to play games with a controller on my TV rather than on my computer (which probably comes from a history of console gaming over PC gaming). In addition, there is talk about improved graphics on selected games, which I hope is optional, and new content in old games. One example was possible unlockable new context in SMB3 that would still look and play and use the same engine as the original, just new levels, etc. I suppose like the new content in FFIV for GBA.
For $5-$10 per game, assuming that $5 buys you an 8-bit game and $10 buys you a 16-game, is this something that would appeal to you? I don't mind paying a little bit, but that might just be me.

