I agree one the keyboard issue. Even the Palm Pre does not have a full keyboard (I assume those keys are tiny, too), so not having experienced that kind of keyboard before, I wonder how much easier to use than the iPhone keyboard it would really be. I am willing to believe that it is a little bit easier, but neither solution would be convenient for writing a novel or something.
The price for the keyboard is high, though: extreme ugliness! The sliding parts thing alone is awful. Even without that, I would expect a keyboard to be prone to getting dirty, and being more brittle than just a flat, solid, iPhone-like brick.
There is another point—international markets. I assume sooner or later Palm will want to expand to overseas. iPhone has it easy—it is all just software. How about Pre—will users be forced to memorize where the keys are, or will Palm incur cost of manufacturing different keyboards?
Palm will incur the cost of making a single part with different layouts for each region, but the cost of this is negligible as to make it a complete non-issue. Companies like Blackberry, and indeed Palm themselves, already do this and laptop manufacturers have been dealing with major keyboard differences for years, so I don't see why Palm will suddenly have any significant problems associated with it.
The price for the keyboard is high, though: extreme ugliness! The sliding parts thing alone is awful. Even without that, I would expect a keyboard to be prone to getting dirty, and being more brittle than just a flat, solid, iPhone-like brick.