Seems like SoE is going to have even more empire-specific weapons and vehicles in PS2 than they did in the original. Anyone else a bit concerned how they are going to get it all "balanced"?

Personally, I think it will be a mess, but probably nothing I will really worry about. I had a blast in PS and will probably have a blast in PS2, imbalances or not.

I understand what you mean IE heavy weapons NC shot gun was OP close up.  However because of full looting capability you can loot and store things you want I had a swag of Terran chain guns and NC Shotguns. (I was Vanu)

When you want to introduce decent, if not polarised, variety in any game with factions, imbalance (or percieved imbalance) is ALWAYS going to be a factor. I mostly played TR in the first PS and they by far had the hardest weapons to master and max suits/vehicles that fell short of the competition by a fairly wide margin. However, that's more or less when I picked them. A challenge is always more fun that insta-shotgunning people to death (NC) as soon as they turn a corner or splash damage murdering groups of people (VS). Once you climbed the frustrating slope of mastering the TR MCG you could take on virtually anyone from any range because it required learned skill at playing the game and didn't need to rely on lazy insta-kill weapons or, in many cases dispicable exploits (e.g. warping) certain legendary NC players used to top the kill tables.

Imbalance can ultimately be a good motivating factor in bringing out the best in the weaker side, not to mention keeping a game interesting for a very long time.

EDIT: what I wouldn't like to see happening is that they take a lazy route (like certain star wars-based MMOs I won't mention), in making the 'different' faction classes direct mirror images of each other, the only distinguishing features being slightly different animation effects. That is very lazy game design. Take a bloody chance, make factions legitimately different. Sure people will moan about imbalance for a while but they do that anyway even with mirror image classes. At least they won't get bored with the game two months in. 

I don't see Planetside as ever having major balance issues, sure the forums moaned all the time but it didn't stop fights from being fair. The game is so skill based that it comes down to the players more than the gear. The only thing I hated was the Deci was so OP that it made Max units useless.

Not everything being the same... is fun.