Glad to see Tactics getting a little love around here! It was actually my first solid introduction to the series/franchise, and it had a fairly decent editor attached to it. Sure, it was insanely light on the roleplay elements and entirely combat focussed, but you could modify the game to insert diplomatic options in various missions. Or just modify the first map to give you a 'magic level up potion.'
There are also the complaints about it being only semi-canon. Way I see it: Whoever has the I.P. rights at the moment is sitting on some fantastic potential to bring the divergent elements together! Those hairy deathclaws in Tactics? I say they're deathclaws in name only, but come from the same government-run genetics program which spawned the reptilian deathclaws we see in the west. Naturally the Brotherhood calls those mammalian monsters "deathclaws" since they look strikingly similar to the old killer lizards back west.
The Pentagon had some of the more successful reptilian deathclaws shipped over, and that explains their presence in Fallout 3. They could also introduce avian 'deathclaws' and the wendigos of Fallouts 1 and 2 could be the cephalopoidal 'deathclaws' (which apparently died out, consider I didn't see any in New Vegas [still haven't finished it or got the DLCs, mind you]).
Vault 0? Who's to say it WASN'T promoted as being the nexus of the Vault Network. We all know VaultTec isn't above lying. Strikes me as entirely plausible that VaultTec and the u.s. government agreed to put all the politicians and celebrities they'd rather not survive through the war in there, and the place was never intended to work.
"Oh yes. You'll be perfectly safe in Vault 0. No, we forgive you for those education reform policies you were trying to push. Trust us. You'll be fiiiiine."
The issue with Tactics not following the dieselpunk-glory-age-turned-apocalyptic-wasteland themes . . . well, yeah. That was a fairly large failing there. It was set in Chicago, but they missed HUGE opportunities for gangster-style material and good old jazz and blues. And the humanoid robots didn't jive with the rest of the setting either . . . but I think there's still some potential available!
In short? I hope they tweak canon just enough to make Tactics part of the overall world story, since it wasn't a /bad/ game, and certainly more deserving than that /other/ Fallout game That Shall Not Be Mentioned.
Edit: Oh, and do NOT buy any of the old Fallout games off of Steam. Go to Good Old Games ( http://GOG.com ) instead. No DRM and you don't need to run third-party software to play single-player games. They also give you free games occasionally and have better sales. I got about 15 Interplay games for $30 during one sale, and I got to pick and choose just the /good/ titles.
