Garmin has released a beta test version 2.93 of software for the Garmin 396 handheld. You can download it at Garmin's website here .
The description of the software is in part cryptic in that it says that it "Modified Aviation In serial data format to work with avionics that do not output linefeed characters." However, the news seems bigger than that. According to a post on the gns480-users group at yahoogroups, the new software now interfaces to the Garmin 480.
Presuming this works well, this is big news for Garmin 480 owners or potential owners. The lack of crossfeed from the 480 to the 296/396 has been a big drawback until now for the 480.
A similar software update for the 296 avilable on this Garmin webpage also indicates that for the 296 Garmin has also now "Added support for tuning SL30/40 comm radios through 'Aviation In/NMEA & VHF Out' serial interface format" -- that is a feature previously only available on the 396.