Depends. A lot of people are critiquing the OS. Personally I feel for tablets it should be a really really good one.
But the way Apple utterly dominates the tablet market, you've got to make it quality and cheap enough to not make people go..."Spend 399 for a completely new tablet on a new OS, when Microsoft has a history of questionable mobile products. Or would I be better off spending 499 for an iPad?"
Then you've got the iPad Mini rumors. But then again to the best of my knowledge prices on both the Surface and mini aren't known. So my hypothetical question could be invalid depending on the price factor.