I kind of fit the bill on this one - I'm pretty bad slob, a handful of times a year I'll get sick of my place being messy and spend a day cleaning, but most of the time what I'll do is a quick tidying up if I know someone's coming over. Mostly its I tend to leave dishes and laundry lying around till the once a week when I clean it all up. That and dusting, I HATE dusting.
I also have some minor issues with time management, nothing so bad that its adversely affected me professionally though, granted it helps that the company I work for is pretty laid back about such matters as long as I'm getting my work done efficiently and the quality doesn't suffer, they aren't going to begrudge me for being a little late on occasion. A lot of that also has to do with the nature of my work - I'm a software developer, so generally speaking when I work isn't quite as much an issue as when I finish a project. If I were on client support, for example, I'd need to be answering phones so I imagine that when I was at my desk in the morning would probably be a bigger factor in how my boss tolerated such things.
I'll admit that I took a bit longer to get through college than 4 years, 6 to be exact, but gaming was far from the only factor. The main thing was for most of my first year I was suffering from a pretty deep depression, my dorm roommate was a raging alcoholic, I really didn't know where I was going in life - I really was only attending college at that point because I was 'Supposed to' more than anything.
I eventually managed to pull myself together though, began taking a wide variety of classes at a community college to figure out what I liked doing, discovered I enjoyed programming, enrolled at another University, and got myself a degree in Computer Science.
I will admit it was an uphill battle moving from being a directionless slacker to actually trying to get my shit together, there was a lot of forcing myself to sit down and study, do homework, etc. instead of playing the latest game I picked up. Really though the thing that changed things from me the most was finally breaking out of the cycle of depression and finding motivation to move forward.
Now as far as how to make yourself actually focus on work when you much rather be playing your latest purchase - for those of you still in college, I *HIGHLY* recommend making yourself do your homework/projects/whatever on campus - I usually used the computer lab, and not at home. I've always found that as soon as I'm at home the temptation to slack off rises exponentially, because generally after you get home from a day of lectures and labs what you want to do is relax and not dive straight back into school.