Not all of them (Mario Tennis Virtual Boy is so long obsolete its ridiculous), but I think it'd be a good time to remake both Virtual Boy Wario Land and maybe Mario Clash now you won't need to use the eye straining red and black colour scheme and that you can judge depth on the 3DS much the same way you could on the Virtual Boy.
Maybe even reviving Super Mario Land Virtual Boy as the 2D platformer for 3DS, now Super Mario 3D Land was a success and a 2D Mario platformer is expected?
http://www.youtube.com/watch?v=hua4kVJDNKc
Would it be a good time to give these forgotten and cancelled games another chance?
Upgrade the colour scheme so it isn't red and black, and simply revive the games themselves, and we could be looking at decent winners here. Maybe even finish the Mario Land game and release that. Even a WiiWare release (instead of having to buy the game on a disc OR cartridge, but still update it and remove the colouration of red and black) would be good. And maybe even update the idea too, like other playable characters and more levels.
Mario Clash doesn't seem like a bad idea. I think they should put an enhanced remake of Wario Land up on the eShop and then release a new 3D Wario game like Wario World for the GC.