Welcome back, Commander!
Man, if you've not been around for the past two years, you're in for a treat. There's TFTD support now, and an explosion of modding activity on which to catch up. First thing I would do is the make a backup of your version 1.0 stuff, then clear out the old executable and files to make room for the nightly so you can take advantage of all the development on top of it. You should still be able to continue your old save file with the latest, but you should probably check with someone else on compatibility issues; I've been diving into mods too much to give a good answer.
FMP has had quite a few updates over the years, Hobbes' UFO Redux has been renamed Area 51 and is nearing it's 1.0 release, and Solarius Scorch started a new project called X-Com Files to delve even deeper into the origins of X-Com as an organization, and that's not even scratching the surface. There's Piratez if you want to go really out there on what can be done with total conversion mods too. So much to do, so much to see, so many aliens to kill!