Brand new Olympus E500 with 2 kit lenses - a wide and medium zoom, and medium to long tele - all for below $1K.
From what you have said it can do maybe 100% and more of all that you want to do with a digicam, now.
Only when you go on to do - if ever - macros, low light, super long range, super wide angle or super fast targets do you need to add lenses and other accessories, and by then technologies have moved and you can consider then what will be the 2nd or 3rd generation from today. And then also you better know what you can and want to do.
So do you have any more cause for hesitation?