Thanks for the replies. Is the sensor size the most important thing, or can a "superzoom" make a difference? I'm also interested in night time shots at
Disneyland, and we're taking the
Disney Cruise to Alaska--thought I might need a larger zoom for whales/seals.
I'm so confused. I have always tried to avoid becoming enamored of the kind of expensive camera with multi-lenses that require photo-smarts.
Sensor size is crucial - probably the most important factor to low light image quality - and yes, a superzoom can make a difference, but in a bad way. Superzoom cameras by necessity usually have the SMALLEST sensors of any digital camera. In order to pack an enormous focal range into such a small package, the sensor needs to be absolutely miniscule so that the lens can be physically smaller too. There are a rare few large-and-hefty superzooms with slightly larger sensors, but none come close to the bigger DSLR-type sensors. Ever notice how when people with DSLRs want to shoot at 500mm like a superzoom does, they need a lens so big it needs it's own zip-code? That's because of the sensor size - a big sensor needs a big optic to cast the light on the whole sensor, and that big optic at the sensor end must have even larger optics at the other end to provide that big telephoto range - so the lens ends up being a foot or two long with many glass elements inside.
For an understanding of the sensor sizes we're talking about, see this:
See that little speck in the lower right (1/2.5)? That's a typical ultrazoom sensor. Also common in most P&S cameras today. That one over on the bottom left (1/1.7) - that's the larger and better sensor that can be found in the Panasonic LX5 or Canon S95. Move to the far right of the next column up, and you can see the micro 4:3 sensor from the Olympus and Panasonic mirrorless cameras - note how much bigger it is compared to the P&S sensors. Move up one more column and you can see the APS-C sensor size from the Sony NEX mirrorless cameras, as well as most entry-level and mid-level DSLRs - even a bit bigger than the M4:3 sensor.
It will give you some idea why image sensor size is very important for picking up and reading the light from a lens, and giving you an image - and why in low light the large-sensor cameras have an easier go of it compared to those little tiny lint-sized sensors from most P&S cameras. Of course, the lens also becomes a very big factor too - because a big sensor needs a lens with a big maximum aperture to let lots of light come through to that big sensor, in order to really get the most out of it.
So yes, you will do much better overall in low light with a large-sensor camera like the mirrorless cameras or a DSLR - but you have to accept the compromise of size and weight - the cameras are larger than most P&S cameras, and even in the case of the new tiny mirrorless cameras (NEX, Pen, etc) the camera has been made smaller, but if you want any kind of telephoto reach, the lens is going to be very big.
You just need to figure out where the best compromise is for you - smaller size, big lens focal range, portable? Travel zoom. Good low light performance - mirrorless APS-C, Micro 4:3, or DSLR. Some slightly larger sensor P&S cameras can be slightly better than the others - those with that larger 1/1.7" sensor like the Canon S95 or Panasonic LX5 will do better than other P&S cameras most of the time, but still won't come close to the big sensor guys.
Another consideration - what will you be photographing in low light? Indoor graduations and things in motion, where handheld low light photography is needed - P&S cameras simply can't come close to even the cheapest DSLR or mirrorless camera. Movement and low light just don't work when your sensor is smaller than a pea. However, if you mostly want to shoot more static or scenic scenes, a tripod will get you great results even with a P&S camera. And some P&S cameras have neat tricks like image stacking algorithms that can even allow handheld low light shots with excellent detail and low noise.
Hope that helps a bit.
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. I'll experiment with low light shots 
using your advice, and see what I get.
