wheel - 1:39 pm on Jul 26, 2010 (gmt 0)
You'll be fine. Certainly there's a limit to how much that machine can handle, but it's likely a lot more than you think. It wasn't that long ago that the specs you posted were considered great, and there's a lot of webservers out there with those specs or lower running fine.
If you want to traffic proof the box, here's some easy stuff you can do that can dramatically improve performance:
1) fine tune wordpress (the program)
2) fine tune your html/css.
3) fine tune mysql
4) add more RAM
5) fine tune apache (I'd do that last). i.e make sure gzipping is on.
And if you're worried about getting hit with traffic, I bet there's tools out there that will convert a wordpress site to a static html site. That would remove most of the processing, disk and database overhead on the machine at which point even that dinky little machine should be able to handle obscene amounts of traffic. But I personally wouldn't bother unless I anticipated a slashdotting.