Apple & App Makers Sued Over User-Tracking
wired.com
wired.com
I suppose the proper thing to do would be to provide a opt-int one-time popup prompt that notified users what you were planning to do... sort of like Visual Studio, Netbeans, or Eclipse in what they do.
Any thoughts on other ways for developing analytics for parts of your app?
Edit: Now that I think about it, it would probably need to be a salt that Apple keeps privately — since bundle IDs are known and UDIDs are fixed-length, those that really wanted to could brute-force UDIDs out of the resulting hashes.
Since the UDID is just SHA1(SerialNumber + IMEI + WiFiAddress + BluetoothAddress), adding in a "vendor ID" at the end when generating it was a huge mistake in the original iPhone SDK, and they can't fix it now.