Since it would seem, you're talking more about living on a boat at a marina while still working, there are some factors you need to consider.
First of all, spending most of your time tied up to a dock, it becomes quite easy for the "conveinences" of home to over run things, making it a chore to cast off for the occasional sail. "Things at rest, tend to stay at rest".
Second, as mentioned in a post above, the type of boat can be much different, if it isn't meant to go out much.
Third, is location. Slip fees and liveaboard fees vary across the country, as well as their availability. Definitely something to look into, before buying a boat.
Fourth would be mechanical skills. Boats need maintainence and paying to have it done can be, and almost always is, expensive.
You need to have realistic expectations of what you'll do, and how much you can do without. There isn't the room for every gadget they try to sell, nor lots of "things" that aren't part of living on the boat. In this sense, it definitely is a lifestyle change, but one that can be rewarding, if approached with the right attitude.
I've met quite a few people who live on boats at marinas, and most wouldnt trade it for living on land.
Another online resource you can check is the Living Aboard Magizine website http://www.livingaboard.com/cgi-bin/ultimatebb.cgi
Good luck with your quest.