Is it worth it?

I used to play GW during the summer of last year and I was really into it when I moved into a new apartment with crappy internet which killed any chance of me playing. I just finished playing WoW (tired of raiding with a cruddy guild) and I want to get back into pvp of some kind and WoW pvp is too biased towards gear for me to really enjoy it.

I have Prophecies and Factions atm, would it be worth it to get Nightfall/Eye of the North if I intend to start playing seriously again? Are they worth it if I'm not serious about playing as well? Also with Eye of the North coming out soon should I just buy the pvp pack for Nightfall or what?

well bud, if all you want to do is play pvp of course you should just buy the pvp pack. Is it worth it? I don't think anyone here can give you helpful advice on that.
Nightfall brings you a fine PVE adventure, however in terms of what you can with it afterwards that leaves 3 things:
farming lightbringer points
farming sunspear points
playing DOA, for which you need to grind LB points. I figure if you're going to start that now you're going to be hopelessly late.
I think it's best if you buy eye of the north for now while that's hot, then consider buying NF when you loose interest.

I've often read that Nightfall has very powerful skills for PvP. I dont really know since i have all 3 chapters and dont remember about the power level differences.
Anyways, for serious PvP you certainly should have all 3 chapters to get optimal choice for builds.

The PvE adventure is nice. Many ppl like Nightfall a lot - personally, it's my least favorite as it seems less demanding than the others. Loooong newbie area and overall many rather thoughtless and easy missions imho. If you like PUGs you will have to play way into the game, say 80%, until ppl start pugging - the earlier stuff gets hero/henched since it so easy (not that you couldnt H/H the end of the campaign of course but ppl are more likely to PUG here). NF has the least PUGs i would say.
I also liked the end game better in the other chapters. NF is still a nice game though so if you enjoy GW it can be a good buy. You know the deal from Factions and Prophecies, the same game with a different story and some new skills.

A good game to buy imho.

I say wait on Nightfall, get Eye of the North which goes live on the 31st, spend the time between now and then getting reacquainted, then if you are still on a Guild Wars kick after you get through that pick up Nightfall, make a Dervish and a Paragon, get them through all the content, and then you can sit and wait for GW2 like the rest of us.

Fair enough. Thanks for the help advice.