I think there will be a crucial first hour of game-play in which the player makes a first series of decisions that might lead them to being in a different starter ship. So, you start in the sidewinder - you mess around a bit, practice docking and travel between a few systems. You decide to look through the BBS Newsfeed and take on a package delivery mission, then you try a bit of trading within a few jumps you have enough cash to choose the Hauler for the increased cargo space. You've made a decision to start off as a trader type, you already have a couple of contacts that will hire you for a little more cash.
If your choosing mercenary missions early on, you might keep the sidewinder. It's that first hour of gameplay that's not in the Beta yet that's going to be crucial into making you feel like you've had a choice about the direction your taking.
I like the reasoning although I suspect that many players with moderate combat skills will be trade-biased in the first few hours, if only to earn enough for the weapons/ship/upgrades to pursue another career.
Btw, were you in the Anarchy extraction zone this afternoon? I think I saw your ship, and may have accidentally zapped you as we went for the same wanted NPC. If so, did the game freeze on you a bit later? It did for me, as it has consistently in that zone for the last two days (usually just after I have built up a nice pile of bounties).
I think I was in the resource extraction zone near Beagle 2 today for about five minutes, so if you were in fact there - that was me. Client was a bit flaky today so I didn't stick around long.