I am at the end of my second year of contract with Three next month, so am in a similar situation to you.
The V3x (
here) certainly looks nice, but I wasn't a fan of the 2G V3 to be honest and everyone that I know who's had one very quickly gets bored of them once they get over the novelty of it's design. The only person I know who's happy with theirs and keeping it is my Dad, everyone else is trying to Ebay or swap them.
Based on that I wouldn't bother with the 3G one as it's not showing many new features or anything that would be of interest to me compared to the 2G one.
The upgraded Nokia soon to be released looks good, may be worth waiting for. I guess it would be annoying to take out an upgrade with the current Nokia now and then next month see a new version released.
But do keep one thing in mind. If these new Three phones do appear, even if you are at the end of a 12 month contract they will still not give you them for free. New handsets on their network are always charged for with upgrades, so you may have to upgrade your price plan or pay some amount for the new handset.
I am seriously considering moving networks at the moment though. Not because I am not happy with Three, I think they are great, but because they don't have any handsets that I want.
This may sound daft to some of you, but I look at the handset as a large chunk of the experience with a mobile phone network, especialy in this day where the phone does more than just make calls.
I want a Sony Ericsson W800i (as does the rest of the world it appears, there's a huge waiting list for them now

) and Three are never going to offer this, so I am seriously considering leaving the network to find another that will offer a similar tarrif and that phone.