First: yes this is just a leak, and I saw some wishful thinking that the leak was on purpose and the real prices will be $100 lower. This seems pretty unlikely given that things leak all the time, and since it's coming out in 10 days someone probably just pressed "Publish" too early.
As a Windows 8 app developer, I wish Microsoft was giving these away for free :-P But I think $499 is a reasonable starting price - you can argue that it's cheaper than the iPad (since the $499 iPad only has 16 GB of storage), but the cheapest one is the same price (although this is ignoring the old iPad 2's that start at $399...and I'm guessing Apple still sells a lot of those?). Of course, that's what the TouchPad started at and that didn't turn out so well, but Microsoft can always cut the price later to juice sales if they want.
And they've already started running commercials, and I think it will get a good amount of press since it's launching with Windows 8.
The touch cover is interesting - my gut reaction was "$119 for a cover??" but then I remembered how awesome it is. Nice that they're featuring it in ads, and I think if people play with one at a Microsoft store they'll understand why it's worth the price.
(for the record, I am totally planning on getting one...probably the 32 GB version with a touch cover. Haven't decided on colors yet :-) )