There was a fair reason why Early Access would be a bad idea. As much as I'd like more dosh for Larian before release, Early Access is getting abused an awful lot and the community doesn't have the patience to wait a year to two and a half years for development in this stage.
Already we're seeing people writing off all early access games. TotalBiscuit slams the practice for the most part ("Unless you're a fan and know what you're getting into."), so it doesn't really work for anyone who isn't a fan of Larian's work to begin with.
I believe it's a mistake, really. This was a bad idea and will damage the flair for full release. They'd have been better off making it a traditional pre-order at most.