chrome os released?

The laws of physics pretty much prohibit increasing clock speeds much further unless something drastically changes in the way processors are made (e.g. photonic computing). CPU makers have been going to multicore not because they like it so much, but because they have nowhere else to go.

But CPUs are still a lot faster. A Core i7 at 3GHz is a lot quicker than an old P4 at 4GHz. That's due not only to multicore, but also because of reduced CPI (Clocks per Instruction) and several other factors.

2 of the same thing does not equal more speed on opening corel and photoshop

In this particular example a higher clockrate won't help either. Opening those applications is likely to be I/O bound, not CPU bound. Your PC doesn't seem much faster because your hard disk isn't much faster than what you had with the Pentium Pro.

But in other cases you are right that straight speed improvements are easier on the programmer. You don't need to alter an app to take advantage of a higher clock speed (or lower CPI, or increased pipelining, etc.), while you do need to alter it to take advantage of multiple cores, and doing that properly is very very difficult.

But like I said, CPU manufacturers are not moving to multicore because they wanted to, but because they had to.