WebOS looks like a nice mobile OS, but it has been extremely slow to get the products to market that made Palm OS successful. I work in the medical field; there was a time that EVERYONE had a Palm because of the selection of medical programs that ran great on their device. Windows ported many of these to their OS, but they never ran as smooth as on the Palm.
The iPhone has many of these programs now, some are FINALLY being ported to Android, but WebOS still supports very few, if any. The only option is to run it in their PalmOS emulator mode, which isn't very appealing at all.
Let's hope that Windows Phone 7 supports these programs...