But on what grounds - looking at his FC record, it's not that special, and without the gloves I'd have been surprised if he'd ever made the side - however, the keeping element got him in the side and now his batting is worthy of a place.
If he wasn't wearing the gloves for WA, his average would probably have been higher, though. Plus, if Andrew Symonds', Brad Hogg's, Brad Williams, Nathan Hauritz's and Shane Watson's selections this year are anything to go by, players are rarely picked purely on stats anyway. All of the best state players train with the Aussie squad frequently and so guys who train with him, play with him and coach him would have a better idea of how good he is well before his stats reflect it. His ability with the bat has been on show for all to see for a very long time and he probably would have been picked despite his FC stats.
Others who've been picked for reasons other than stats:
Glenn McGrath - had played only 8 FC matches before being called up. Sure he was bowling BEAUTIFULLY but there certainly would have been a temptation to give him a longer stint in state cricket before picking him. However, his sheer ability forced his way into the side, not to mention (I'm sure) the testimonies of those who had trained and played with him for NSW.
Jason Gillespie was picked after one full season for SA (albeit, a good one where he topped the wicket-takers for all states).
And of course the most obvious example is Warnie, who was averaging around 40-odd for Victoria when he was picked to play against India. Obviously he didn't succeed immediately but people saw beyond the mountains of chips-induced lard and saw a player with a very special talent. When he then picked up 7-52 against the West Indies the very next season, having taken 3/11 against Sri Lanka in the Aussie winter, the rest is history.
I'd venture to say that MOST of the great players are picked with justifications which don't take into account their FC record. It's the ability to see past that and to determine just how good a player is which makes a good selector and good selections. Gilchrist would have been exactly the same, people would have seen his ability and I'm sure he would have been picked, regardless of the fact he was averaging in the high 30's for WA and completely disregarding the idea that he probably would have had a better average if he weren't a 'keeper.
Players are NOT their stats, people.