I got the same offer and I am considering it if not for the International Upgrades alone. I guess you get 4 of them. On the web site it says 2 for yourself and the other 2 for a companion but I assume you can use them yourself?

What fare basis do you have to have to use those certificates?

On a positive note: I flew US quite a bit lately (mostly because my UA flights out of SFO or OAK were delayed or cancelled...) and I enjoy connecting in PHX. All the flights I had so far were on time and all my upgrades cleared. Looks to me USAir is gettting there