Good draft for the Raiders I think. The team doesn't have any major weakness right now other than age at a few positions. No obvious first year starters, but they are filling in depth at positions where they will need a guy in a few years.
Asomugha (31) is a big DB who runs like hell. Probably will end up at safety, replacing R. Woodson in a couple of years.
Brayton (32) will help them at DE, where they need help with the decline of Armstrong. My understanding is that Brayton is a tweener and can play DT too. Should fit into the platoon DL concept the Raiders use. I still think they have to either trade for or sign a star pass rushing DE to move the defense to the next level.
Johnson (63) is a cool pick I think. He is another tweener, a WR in a TE's body. He's probably too slow to start at WR but the Raiders use a lot of multi TE sets where he will be perfect.
They got an LB and a RB in the 3rd. The RB is the son of Huggy Bear from Starsky and Hutch.
Round 4 they got an undersized DE who runs a 4.4 40.
5-6-7 they got a WR, a tackle and a safety.
Nothing huge in there but I think they dealt with their biggest needs. We'll see how good these guys turn out to be.