As with every other product, I have no intention to pay good money for working as a beta-tester, so I'm going to wait to see how ready the game turns out to be after its release*.
It'd be nice if we got a combination of ME1's story and free hand with ME2's characters and gameplay, but, so far, everything points to more ME3: a cinematic experience with railroaded characters.
I hope that they will, at least, make modding easier to compensate for the Bioware-typical desinterest in exterminating bugs and adding gameplay options.
* If ME3 hadn't been a gift I rather doubt I would have ever given money away for it. It would have been different if there had been a Game of the Year Edition with all DLC after a year or so, like CD Projekt Red did with their Witcher series, but it looks like EA still thinks it's totally reasonable to expect anyone to pay a hefty sum for a complete game even years after the final DLC release .. that's a business attitude I don't want to support at all.