I have to say, if you're buying just the laptop and you don't want the upgraded processor or more RAM, then definitely get yourself down to an Apple Store and buy it.
Like some people have said, if something goes wrong, you have to send it back to Apple and wait a few days to get it back. Where as if you buy instore, they're able to diagnose, and in some cases fix, the problem right there and then.
In my case I bought my UMBP 2.53Ghz, a few days after they were released in October with no hardware upgrades, in store. it developed a fault in April for which I had to hand it back in to the store for a few days to have fixed. As soon as I got it back I realised it was worse than before. They put the DVD drive back in incorrectly, the lid wouldn't close properly, etc. Because I had taken it to the store that I had originally bought it from, the Mac genius just gave me a brand new one with the upgraded 2.66Ghz Processor.
Now imagine if I had bought it online and was obliged to send it back via post to get repaired. Factor in the time it takes to repair, postal times, if repair caused more problems then that meant more postal time, more waiting around, you get the picture right?
That whole process I went though would have taken ages had I bought the item online.
So I would definitely recommend buying in-store where possible. Its just so much easier to kick up a fuss and get your own way in person!