The E5200 is basically a cut down Wolfdale core at 2.5GHz with 2MB L2 and an 800MHz FSB and will replace the current E2x00 line. It ain't gonna break any benchmarking records but at $84 USD it looks like a great option for budget overclockers, especially if retail samples can overclock as well as the ES. Its supposed to launch sometime this quarter.
I just got my e5200 to 4.16ghz, was my cheap upgrade from my overclocked e2160. I didn't even change the settings and it is running smooth and cool. It has yet to go over 47C during burnin and its been running Prime 95 for 3 hours. I am pretty tempted to go higher.
I have the Gigabyte GA31M-ES2L board and e5200 processor. I have an aftermarket zalman cooler in place. I'm not interested in taking the processor to it's limits but just wanted an easy clock speed increase. I upped the FSB to 300 mhz with the default 12.5 multiplier (now 3.75 mhz) and manually dropped the RAM freq so that the RAM stayed at 800 mhz (2.66). I have yet to stress it with Prime95 but is running stable and cool. Core temp in the BIOS went from 25 C to 34 C. We'll have to see what an overnight burn-in yields.