Roughly a 1000 alpha slots are gone each week. So if you are on the fence for whatever reason then you are running out of time. By the time the Dog fighting module is released it will be all gone and no way to get in on the action until the release in 2015ish. Unless they add more slots, which has happened once. But there was a lot of talk about doing that before they added some slots. Haven't heard anything this time so I would just take the leap and jump right in it while I could. For 45 dollars you get alpha and beta access and the full game of Star Citizen and with that Squadron42 (Which is big enough to be a completely separate game) Damn good value for you 45 dollars. They even throw in a ship for you!
I'm annoyed that team Damage and team AEM got eliminated from the Next Great Starship comp . You would think that a pair of automotive designers would be able to come up with a decent ship (Damage).
Anyhow... I've backed for a Constellation and a Hornet, myself. As far as alpha slots go, I would imagine that they would increase the capacity of Alpha slots as they did last time around. It also appears as though they secretly add a couple of alpha slots on a daily or weekly basis. I've added the last digit of taken and available alpha slots every now and then, and sometimes I get an odd number, sometimes even. Something sneaky is probably happening behind the scenes