There have been numerous updates to various components of Lync 2010 over the last two months, including core server components, Group Chat, conferencing, web components, UC Managed API 3.0 Runtime, and clients of all stripes, with the notable exceptions of Windows and Android clients which have not been updated since November and December of last year. Many of the server-side updates probably didn’t appear in Windows Update for you until just last week.
My edge server is fully patched, and I haven’t seen any problems with it. If anyone else has seen anything differently, tell us about it in the comments. I’m going to update my internal Lync server soon, and I’ll let you know how that goes.
Update 5/7/2013: All Lync servers fully patched. So far, so good.