Alleged Galaxy S5 SM-G900A version for AT&T pops up in a user agent profile
Naturally, the UAProf could be of a prototype device, so the reported specs and resolution might be far from final, so the takeaway here is that there is indeed a Samsung SM-G900A in the testing phases, just as the SM-G900F and SM-G900S versions, which already made their benchmarking rounds.
source: SamsungMobile via GalaxyClub.nl
Things that are NOT allowed: