Overclocking, I think, is great. If you have a CPU that overclocks well, I see no reason not to do it.
If you increase in small steps, don't rush it, follow guides, it is pretty safe. It is a lot safer and easier to overclock now than it was a few years ago.

My old pc had a 600mhz on it for 5 years and was fine.
The i5 I have atm has a 900mhz overclock on it and is running great.

If you can squeeze a bit of extra speed out of it, why not.
If you're buying a new build every 2.5 years which is going to be top of the line, yeah you don't really need to overclock, as it will run everything maxed out anyway :P
Rich fucker.