Well, the very first loading delay has to do with relighting, always give it a long time before deciding it\'s frozen. If it took any less than 100% of your CPU at startup, then it would take a lot longer to load.
Once you\'re in game, many people experience very low (~1-10) fps, which many mistakenly label \"lag\". This is just due to general suckage, even if you have very good hardware. Hopefully some of these problems will be remedied in the next release.