With the modern Li-Ion batteries in MBPs the old concerns about batteries losing the ability to hold a charge if plugged in all the time no longer apply. Li-Ion batteries LIKE to be kept topped up, and don't like deep discharges, so it's better to plug in your MBP whenever possible. In your specific case, you deep discharge your battery by taking it al the way down to 10%, so each practical cycle is a full-cycle. If you were to change your habit to keep it plugged in when you can and definitely recharging when it gets to 60-70%, you'll get more lifetime out of the battery. Not more cycles, that's still about 1000, but if you use external power when you can, and don't deep-discharge the battery, the calendar time to use those 1000 cycles will be increased. While it's not absolutely rigid, two 50% cycles are roughly one full cycle, etc.
My MBP stays plugged in at my desk most of the time, with the exception that I let it deep-discharge about once a month to let the OSX system re-calibrate the battery meter settings. On the other hand, the object of a laptop is portability, so don't be afraid to take it on the road. 1000 cycles are a lot, and the battery doesn't fail at that limit, it just starts to decay.
EDIT: Pigoo3 beat me to it, and was much more brief, to boot!
