Getting a first "real" camera (but still P&S)

I've never gotten that into photography and still have (but don't really use) a 5-year-old Optio.
I'm looking to get a camera I will use a lot more. Right now I'm interested in the A630 and A650, maybe SX100IS, maybe even G9. Also looking at the Sony DSC-H3 and some of the Panasonics.
I actually do want to have some manual controls so I can learn something

How important is the IS for low light or motion shots? Some people say that high ISO performance is actually more important because it helps when the object is moving too. Is it better in some of these cameras than others?

In the past I've tried to take pictures in social situations in low light and they usually come out badly (sometimes even when the light isn't so low). Ideally I'd like to be able to take pictures of people dancing in moderately low light, maybe I really need to get a different camera for that one (bridge camera)?

I also dislike long shot-to-shot times. Are there tricks that improve the speed of the A650 or G9?

A lot of people really seem to like those rotating screens -- I don't know yet if I'd use it much, but I'm guessing I'd find uses.

Just some thoughts and questions from someone who wants to get more frequent and better pictures in life.

I'm not going to try to answer all your questions, but:
IS and high ISO are complementary. High ISO will stop subject motion, true, but at the expense of noise in the picture (usually called "grain", a holdover from the film days). IS helps especially when you're using the LCD to compose your shot, since that means, invariably, that you're holding the camera out at something approaching arms' length rather than with a nice, snug brace against your forehead. Personally, I use my optical viewfinder 90% of the time. The only time I use the LCD, it seems, is when I'm using the flip-out capabilities of the screen. And when I use it then, it's often for a shot I wouldn't be able to get with my SLR (over the crowd, into an aircraft cockpit from the ground, etc.).

I don't think there really is a "bridge camera", good at low light levels and fastish shutter speeds but still pocketable. My best suggestion for that would be to add an auxiliary flash to a PowerShot. But even the Canon dedicated PowerShot slave flash will add to your camera's bulk, and the flash going off won't be any too popular in many situations. But high ISO without noise needs large pixels, which means a large sensor, and fast shutter speeds mean either high ISO, fast lenses, or both.

Setting the camera in "Continuous" will let you get 2-3 shots every 2 seconds; you need a light touch on the shutter to avoid getting 2 when you want 1, and have less precise control of the individual shots, but it's a possibility.

My mom had a Canon with a screen, and she didn't find it very useful. If you extend it out and flip it around, you're usually really close to the screen. You also risk it breaking by using it - not high but anything puts pressure. If I take self-portraits I simply guess and take another shot if I'm off.

Point and shoots usually suck in low light. Period. Actually I have not tried the higher end ones; my primary experience is with Nikon, and even with AF assist beam it kept racking up red light no-focus situations. Kicking up the ISO resutls in even poorer pictures. Perhaps a higher-end P&S Canon will have less problems.

Tilling wrote in post #5747486
How important is the IS for low light or motion shots?

Very important.

All small sensor cameras give you bad performance in low light. That's just physics.

I think only an SLR will be able to take good shots of dancing.

I understand completely. But there's really no limit as to how much money you can spend - the more you spend, the better the pictures become. Faster autofocus, being able to shoot in lower light and print larger. There are photographers on here who shoot weddings and their camera setups are expensive. 5000 dollar body, 2000 dollar lens and a 300 dollar flash - they can shoot low light action easier... and even they are pushing the limits of their equipment.

I think for beginner photographers it's better to make a clear distinction as to what you want to do. If you want to study photography, then any camera with manual controls is fine. You won't be able to shoot in low light, but you'll be able to learn the art.

The other side is technical - to have a high enough shutter speed at low light, you need an expensive lens with an expensive camera. The gear allows you to shoot in a tougher conditions, but doesn't necessarily make you a better photographer.