External Storage
Currently, the 5ooGB Western Digital My DVR Expander ($200) is the only “TiVo Verified” external drive – good for about 65 hours of HD content. However, a variety of eSATA drives will work just fine – if you’re looking for more storage or a lower price point, review this thread. FYI The WD drive doesn’t have the TiVo guy on it as pictured (sorry) but should show up at the TiVo store shortly.
Multi-Room Viewing
Video transfers between and amongst both Series2 and HD TiVo units are now available. The only (unsurprising) caveat being that Series2 units are limited to standard def content.
TiVoToGo
TiVoToGo video transfers to computer are also being enabled, including HD content. Current methods for playback and conversion, including the official TiVo Desktop (PC) and Roxio (Mac) software, should work fine.