Jo pointed me at this recent email about progress by Kragen Sitaker on scanning the first edition of the OED (from looking at the front pages it looks like this copy has come from Harvard University library).
Currently he’s up to volume 6 (L,M,N) and has also produced a nice web interface to let you browse and search through the scans. He’s also encountered the usual copyright questions but the first-edition OED does seem to be safely pre-1923 (and therefore public domain in the US) though some lingering doubts remain about the last fasicles (W in particular).
As detailed in his original email the aim of this is not only to make the OED available but also to allow for future development in an open fashion. This approach is particularly suitable for the OED not only because dictionaries granular character naturally lend themselves to incremental, decentralized working methods suited to open knowledge development but because the OED was itself initially developed in a fairly communal way with thousands of people from around the world contributing snippets to a team based in Oxford.