At this point in time, it really doesn't matter as much as it used to because Microsoft (of all people) has provided you with a good excuse: It doesn't make any difference anymore because Windows Mobile is being discontinued. People have already stopped making software long ago (Firefox Mobile, for example), and as the date of Windows Mobile's demise approaches, people will continue to cease development for it. Just like you stopped seeing people selling Palm OS apps shortly after Palm halted the Palm OS, you don't hear about Windows Mobile apps anymore, and 5+ years down the road (when the hardware is really outdated), people will quit Windows Mobile in droves. Sure, they can still sell the software after it is outdated, but people no longer buy it, so it'll be like the Palm OS is today - there, but not a big staple anymore. Depending on the obsolence of the product, you may wish to still support the developer, but if Garmin has moved on to "bigger and better" (at least their idea of "bigger and better", android, Apple, WebOS) then it is really up to you.
Or maybe I'm being too cruel?
You decide.
- 2 Bunny