Hmm, could be a good time to pick up another Vista HCx cheap ...
Perhaps the best thing about the new unit is it's lost the rubber band (
or has it). For the rest, it will probably be broadly similar to the 62 series, ie the 'new' Garmin OS (like Dakota etc) but hopefully with the option to switch back to old-style menus (like the 62 can). The high-colour screen without the touch membrane to turn it to mush, should be great - though the terrain shading looks great in the pictures, I think most users soon turn it off. And I expect it will run OS maps if you want to pay through the nose.
The mount works well enough and fits on stem as well as bars.
From this
German Garmin press release (pdf):
5.3 x 9.9 x 3.3 cm
142g inc bats
Display 5.6cm diagonal touchscreen (?!) 65000 colours 128x160 px, rotatable
...
Galileo-compatible
1.7Gb internal memory
microSD card
(30 adds ...)
3-axis compass
barometer
ANT+
the touchscreen reference is, I hope, a mistake! - and the resolution as well (current Etrex C is 176x220, Dakota is 160x240)
The big internal memory plus SD card means that like other new-generation Garmins it will handle multiple map files, which is a definite plus.