DeLorme has announced an anticipated ship date of the week of January 15 for its Earthmate GPS PN-20. The long-planned Earthmate PN-20 ships with the national edition of DeLorme's Topo USA 6.0 and is capable of accepting USGS topo maps and aerial imagery using DeLorme's proprietary Aerial Data Packets (ADP).
The PN-20 also comes with routable maps covering major highways and roads, and a world-wide base map. Here is a link for more information on ADP's and included maps.
I criticized the cost of ADP's in my book, GPS Mapping, which (at that time) averaged out to around $155 per USGS 7.5 minute quad). DeLorme appears to have dropped the price down to $0.25 per square kilometer, but by my calculations, that's still almost $40 per quad.
Regardless, I'm happy to see raster imagery on ruggedized handhelds. Bushnell is also introducing models with this capability. Over time, I hope we'll see some handhelds using non-proprietary formats for this sort of imagery, but I expect that will take a few years.