I like it a lot but there are a few sites not caught up to it yet, of course how could they, one most annoying one is getting an invite to try Riya and now not having a brower to do so on the machine I want to (i'll use a different one with Firefox of course) and also it has messed up the otherwise very nice looking KLM site, what's interesting for me is how a nice use of AJAX has been screwed by a browser upgrade!
Also when I put a search term in the Live Toolbar it loads a new tab with Live.com in it and not the result set, minor glitch but annoying none the less!