Just because you have 2GB of RAM doesn't necessarily mean your system is not using the page file unless you turn it off. The CPU cache reads and writes to system memory and to the page file, and yes, it does it at full processor speed so unless the program is very cache-dependent, you normally would never notice it.
I agree 100% that dual core is the way to go. 99.99% of people who use computers would gladly trade a few frames-per-second for better system responsiveness. This trend is only going to continue, making a dual core purchase now a smart one, providing you're not piching pennies to get it. To me, a $150 difference in price is cheap if I'm not planning on upgrading the processor for a year or so. As I said in an earlier post in this thread, hardcore gamers are only concerned about frames per second, making them less likely to recommend dual cores, but all games developed now I'm sure will be coded to take advantage of multiple threads, so it's only a matter of time before the entire industry has moved to dual core. I'm sure there will still be single cores available, though they likely will be budget processors in the foreseeable future, much like the Celeron. It may not entirely happen this year, but it will happen. No doubt about it. My guess is sooner, rather than later.