Maybe i can simplify this...here goes.
Yes, you'll get to a point were your weight stabilizes. At that point your calories and/or cardio must be adjusted.
At the point that you stop losing weight, you need to either futher reduce caloric intake, or do more cardio, or both.
Theres other variables like what BF% your at, if your metab has stalled etc. but this is the basic rule of thumb for weight loss.
EX. If your losing weight at 1hr of cardio a day, taking in 2500calories. At some point you'll stop dropping pounds. At that time you could either do 1 1/2-2hrs of cardio, or drop to 2000 calories. These are just ficticious #'s, but its the general idea.