Overall, the new Wolfdale is faster, not so much in general applications but it shows some notable performance improvements in 3D rendering applications, along with mixed results when it comes to gaming:
Gaming performance is a bit of a mixed bag; we saw everything from Oblivion's 0.4% performance improvement to 8.5% under Lost Planet. Wolfdale is good for gaming, but the degree is very title dependent. […] On average, Wolfdale ends up being just under 5% faster clock-for-clock than Conroe. Definitely not an earth shattering improvement, but an improvement nonetheless.
Being based on a 45nm process versus the 65nm process of the E6550, power consumption is down by around 10% and that of course means cooler temperatures too. Further on, they went on to do some overclocking and managed to push the CPU all the way up to 3.22GHz. You can head on to AnandTech to read the complete Penryn Preview.