It'll be awhile before I can get it, so I'll just answer some of the questions posed.
All Pocket PC 2002 PDAs have interoperable software now, since Microsoft declared manufactures had to use ARM compatable processors (instead of a choice of three in Pocket PC 2000). So, HP I-Paq software will work on this (with a few exceptions of apps that use low-level features of the I-Paq). Also, any previous WinCE/Pocket PC 2000 apps for ARM or StrongARM should also work.
Of course it will play MP3s, and WMAs, drag and drop using the included software. Divx (have to re-encode it to smaller size), and MPEG video files can be played with third party software (full color and sound, most players let you play the movie full screen[sideways]).
Storage hungry? Plug a 1 or 2GB microdrive into the Type II CF slot for your video and music needs, or if you really need space get the adapter Dotman mentioned, and use it with a portable harddrive kit. (Needs to be PC Card/PCMCIA and fully ATAPI compatable. Cardbus and drives requireing special drivers can't be used)
Battery life? Not sure, Intel says X-Scale should be less power hungry than the StongARM, but I guess looking at reviews would tell you that stuff, and of course varies on what apps you use and what the backlight is set too.
Want more reasons to get one? How about a built-in internet browser (PIE) that, using separate compact flash modem,Compact Flash NIC or cell phone (blue tooth w/CF adapter or IR), lets you surf the 'net on your palmtop (not just WAP, but full fledged internet, you can even get Flash plugins). Very cool!
Dotman: Do you know if that adapter can fold all the way back, letting you put the PCCard behind the PDA? I know it says flexible, but I'm wondering how flexible.