According to alternative tentaclesthey will be releasing both the mangled demos and pigs of the roman empire on vinyl this August. Also in late September they will be releasing the second installment from the Jello Biafra and the Melvins collaboration reportedly titled 'Sieg Howdy', a 6 track ep this will include remixes by Al Jourgensen of Ministry, Dalek, Dale, and a cover of Alice Cooper's Halo of Flies.
A good review of the Mangled Demos complete with full mp3's has been posted by Buddyhead, you'll have to scroll down to June 2nd.
Also Daniel sent me a heads up that the Melvins are playing All Tomorrow's Parties "Don't Look Back" where they will be playing the Houdini album in its entirety. This is taking place on the 4th of October this year at the Koko in London, England. Tickets are £17.00 and are available here.