I've been happily using my Sharp LH79524 on a Logic PD card engine in my design to control the display of a boiler exhaust gas analyser and I've cracked most of the technical challenges leaving just the application to be plugged away at.
However, some nice sales people have come in to talk about LCD panels but also plugged a PXA270 board they were selling (for less than the Logic PD board). I've had a quick look at the specs and peripherals on the xscale and it is gusset-moisteningly funky. It's quick and has powerful LCD support and also takes a camera input which might be useful. The dedicated MMC/SD interface is also highly desirable (and could have saved me a good bit of time). It also comes with a good whack more RAM and Flash than the Sharp (128/128 as opposed to 32/16) which is always nice to have.
It comes with Windows CE on it, which puts me off a bit but should make using the hardware easier but then I've already got the hardware running how I want it on the Sharp.
I think if we'd looked harder at the Xscale 12 months ago we may have gone that way but it wouldn't be impossible to change now - our compiler and other tools are for ARM so they should work on the Sharp or the Intel and my application code is system independent. The question is - is it worth changing?