Believe it or not, approximately 5 months are SQL 05 went RTM, Microsoft has released the first service pack for that which includes the database mirroring functionality. You can get a list here of all the things fixed and the press release here . I have not tried this myself yet, so cannot comment, but I wonder if it would cause any issues to BizTalk and SharePoint among other things. I’ll post any issues I find over the next few days here.