Well, seriously are you sure 520 won't get it?Sorry if I did..
I always love how people get a low end device and feel they should get all the features of a flagship device. There's a reason why it's cheap.
It's likely that when WP8.1 comes out even more features will not be available for the 520 and it's likely some features won't be available for the 920 either. Such is life.
Cry me a river will ya?
How wickedly true! But with whatever features WP 8.1 will be available for 520 right?