My team (Excel Server) is currently hiring developers. It's a great team to work on and we do some cool stuff. Since we're still a fairly new team (we just shipped version 1.0 with Office Server System 2007), there's still lots and lots of new code to write and you'd have the ability to have a very impactful influence over the future of the product. Here's the "official" blurb:
Microsoft Office is looking for talented developers to work on cutting edge web-based technologies that integrate with Excel and Access. It’s a great opportunity to work on cool new features and build great products. You may have already heard about Excel Services that we shipped with Office 2007 (if not you can read more here http://office.microsoft.com/en-us/sharepointserver/HA101054761033.aspx and here http://msdn2.microsoft.com/en-us/library/ms519581.aspx) and we’re building on that story as well as pursuing some other new ideas.
If you know someone who might be interested in the position, please contact email@example.com. For more info, check out this job listing: http://members.microsoft.com/careers/search/results.aspx?FromCP=Y&Keywords=HA101054761033
If you're interested you can either contact me directly (firstname.lastname@example.org) or the address above.