The best thing you can do is learn all of the manual features and get good shots with your point and shoot (it's possible). Once you've outgrown your point and shoot move on to a DSLR.
There is 2 main things to keep in mind:
1: MP means nothing if there is a crappy lens.
2: DSLR has a larger sensor (usually lacking a "video preview") and a larger lens which will allow more light and also gives the camera better low light operation.
All of the cameras work the same in manual mode, but P&S cameras are hindered by the small amount of light that enters the camera and their lack of ability to process it efficiently. When your P&S camera just isn't cutting it, add more light.
I shot this pic with a Kodak DX7590 point and shoot:
I had the tank loaded with light, but it's what it took to be able to shoot with a fast enough shutter and a low ISO. If I raised the ISO the pictures were terribly grainy do to the cameras inability to process light efficiently. If you stick with a point and shoot, make sure it performs well at ISO400 or higher. Check out
www.dcresource.com for a write up on whatever you're trying to buy. They've got some of the best reviews I've seen.