According to a recent Myspace post, The Melvins are playing a couple of shows with Grunge forefathers Green River in Seattle:
More Silver Anniversary fun!! The Melvins will play two special shows with old pals Green River. The dates are May 22nd and 23rd at the Showbox At The Market in Seattle, WA. Check out the Green River Myspace here,
http://profile.myspace.com/index.cfm?fuseaction=user.viewprofile&friendid=364525415
Sounds like a good gig to me!