It matters how much less, especially depending on the specs.
If this is essentially a souped up Gamecube, as IGN has suggested in the past, $299.99 would be a bit pricey, IMO (unless they bundle Wii Sports and a second wiimote with it or something). The difference between $199 and $299 is a significant one.
VC costs are a big factor too... if the VC is charging $10 a title or something, that's an important thing to know. Did you guys see what Sony was charging for some of the stuff they showed for Sony Live? $7 for a downloadable "level" of a game? I mean, I guess anyone who's spending $600 on a system has no concept of the value of money, but even so.
They did just enough to convince me to not buy a 360... but not enough to convince me to preorder a Wii... I need a lot more info.