UIDevice uniqueIdentifier deprecated - What to do now?

Question

It has just come to light that the UIDevice uniqueIdentifier property is deprecated in iOS 5 and unavailable in iOS 7 and above. No alternative method or pr

Answer 1

Based on the link proposed by @moonlight, i did several tests and it seems to be the best solution. As @DarkDust says the method goes to check en0 which is always available.
There are 2 options:
uniqueDeviceIdentifier (MD5 of MAC+CFBundleIdentifier)
and uniqueGlobalDeviceIdentifier(MD5 of the MAC), these always returns the same values.
Below the tests i've done (with the real device):

#import "UIDevice+IdentifierAddition.h"

NSLog(@"%@",[[UIDevice currentDevice] uniqueDeviceIdentifier]);
NSLog(@"%@",[[UIDevice currentDevice] uniqueGlobalDeviceIdentifier]);

XXXX21f1f19edff198e2a2356bf4XXXX - (WIFI)UDID
XXXX7dc3c577446a2bcbd77935bdXXXX - (WIFI)GlobalAppUDID

XXXX21f1f19edff198e2a2356bf4XXXX - (3G)UDID
XXXX7dc3c577446a2bcbd77935bdXXXX - (3G)GlobalAppUDID

XXXX21f1f19edff198e2a2356bf4XXXX - (GPRS)UDID
XXXX7dc3c577446a2bcbd77935bdXXXX - (GPRS)GlobalAppUDID

XXXX21f1f19edff198e2a2356bf4XXXX - (AirPlane mode)UDID
XXXX7dc3c577446a2bcbd77935bdXXXX - (AirPlane mode)GlobalAppUDID

XXXX21f1f19edff198e2a2356bf4XXXX - (Wi-Fi)after removing and reinstalling the app XXXX7dc3c577446a2bcbd77935bdXXXX (Wi-Fi) after removing and installing the app

Hope it's useful.

EDIT:
As others pointed out, this solution in iOS 7 is no longer useful since uniqueIdentifier is no longer available and querying for MAC address now returns always 02:00:00:00:00:00