Windows 10 Tech Preview looks good already, I've tried out every build so far in a virtual machine from day one, and I have to say - Good work so far Microsoft. I am hoping that with the next build they will allow you to change Cortana's default search engine because I'd hate for her to search with Bing all of the time... I mean it wouldn't bother me too much once I get used to it but I use Google over Bing so... There's that. Besides that and a few bugs and incomplete things I think the Tech Preview is shaping up to eventual release... Hopefully soon, but no rushes.