basically dual core are really good and make your applications function faster. And that is good for having a work done in shorter time.

Yes I know it's faster but for now only a few software’s outthere can take advantage of the dual core technology. Windows is one and a fewmore, game developers are still waiting for someone to find out how dual corewill help them. And why go for it when prices are still high? I'll just waitfor the quad cores and other multi cores to be launched then the prices of dualcores would definitely drop.

Obviously, Dual core. It gives you faster processing speed. However, Core 2 Duo has 2 MB memory cache whereas Dual Core has 4 MB memory cache. The more memory cache you have, the faster your data processing will be.  

Alright dual core is faster, what will be the difference if they will install an 8 MB cache for a single core processor? Will it perform better than those dual core's with 4 MB of cache?

I have Core Duo processor on my laptop and its working really good. Intel P4 with Dual core also has a good review because of its memory cache. I would recommend you to use the latest processor for good computing.