I've got the same problem I've read that other people are having here involving the svchost using 95-100% of my cpu usage. If I kill it, the major problem seems to be that my sound no longer works.
I've tried some of the methods others have here, with no effect. Upon further investigation into it, it seems to be my DHCP client. If I disable it, I have no more svchost problem. Unfortunately this also makes it impossible for me to connect to the internet over a wireless connection.
Any help would be greatly appreciated.