I don't even consider replay value when I buy games nowadays. If I really want to play through a game again (and it isn't sixty hours long) I will, but whether or not it would be worth doing so doesn't factor at all into my initial purchase.
Given the supposed power of the new system, I wouldn't be surprised if Nintendo starts offering a Virtual Handheld service this time around. Of course, people would complain that they couldn't play their two-generation-old games without paying for them again, because the GBA is almost certainly fresher in people's minds than the N64 was when the VC went online. In fact, they already are complaining about it.