I think you're being unrealistic. We're definately going to gain a few seats, but I don't see how nine is within reach. From your list, 4, 5, and 6 are exceedingly unlikely. I think Louisiana is going to switch to the Republicans as well.
I'm just showing a scenario in which the Democrats could reach 60 in the Senate. This is of course contingent on a strong nominee (read: not Hillary), a downturn in the economy, the war malaise continuing, and Bush's approvals staying in Nixonland. If all those factors occur, I don't think this scenario is unrealistic.
It's also possibility that significant progress is made in Iraq, Bush's approvals rise to the low 40's, the GOP nominate Giuliani or Romney and runs an anti-Washington campaign, the Democratic Congress continues to alienate its base, Hillary runs a play-it-safe campaign, Johnson decides against reelection and Landrieu faces off against Kennedy.
Basically, it's impossible to tell this far out what the conditions will be like come October 2008. Even in September 2006 (before Foley), most people would've thought it absurd that Democrats would win races like KY-03, where the Democrats were saddled with a fourth tier candidate.