Well I should firstly qualify this post by saying I definitely wouldn't have had him anywhere near the team and I realise the following isn't anywhere near convincing enough as an argument to justify his selection, but I thought I'd offer some very tentative optimistic thinking about him that hasn't been offered.
The main positive I see to Beer is that he isn't a proven failure at First Class level with the ball. He's proven absolutely nothing either way, but is that really more of a sin than picking a someone who has proven he categorically isn't up to it? Since the retirement of Warne, the selections of Hogg, Casson, Krejza, Hauritz, Smith (to an extent) and Doherty have all been just as big or even bigger 'gambles' than Beer in many ways, as these players had all proven over reasonable careers that they weren't up to the mark even at the level below. Now a lot of these players were young so to completely write them off would be silly but they'd certainly shown over their First Class careers that they were not Test standard at the time of their selection. They were picked in hope - some in hope that they'd prosper in different conditions and some on the basis on small sample sizes of "improvement" after years of failure. Beer has at least been performing as an absolute standout in the competition he's been playing most of his cricket in.
Now, there really is absolutely nothing that should put him ahead of O'Keefe in the pecking order. They both dominated grade cricket and they both bowl similar stuff but O'Keefe's had more First Class experience, performed to a better standard in the First Class games he has played, performed for Australia A, can bat to a MUCH better standard etc etc. But compared with someone like Hauritz or Doherty there is 'some' logic, even if I don't really agree with it.
Just thought I'd throw it out there. To summarise, what I'm basically saying is "at least we don't know he's rubbish".