That phone has:
windows (mobile or CE, can't tell)
(2x) qvga (320x240) resolution
no wifi
afaict, no bluetooth or 3G
probably quite weak cpu
So, no thanks, I'd rather have my Pandora.
There simply are no other pocketable devices <$400 with Pandora's performance and flexibility*.
There are a couple devices that come close, but none can consider themselves a real competitor to Pandora's niche:
The Nokia N900 is a pretty similar device, just no gaming-controls (use a bluetooth-controller), less connections(but it does have 3G and 32GiB of built-in flash), and significantly more expensive.
The Archos 5 is similar in specs, has flash storage, is cheaper, but no keyboard or gaming-controls, and a locked-down default os.
The Odroid is also similarly specced, does have some gaming controls, is cheaper, has a hdmi-port, but only a 320x480-screen, no keyboard, and a smaller battery.
The current Ipod Touch is about the same performance hardware-wise, cheaper, but its screen's resolution is far lower, and it's far less flexible.
Cheap netbooks are more powerful, but not pocketable.
There's a whole host of <$300 slider-phones and other devices that are (far) less powerful.
* meaning battery-life, controls, connections(physical and wireless), and openness of the software. Just everything that makes it possible to use it in a particular situation.
