Hello Seabody,
Glad to see my previous explanations helped you!
If I remember correctly, you have Late Night (6.something) but not Outdoor Living stuff pack, right?
Then you'll need to download the new patch for the Base Game, indeed, so a "1.something", and the new patch for Late Night too (a new "6.something"). Since you have fully patched you game recently, and are thus on latest patch level before Generations, the incremental patch will be enough.
When you get Generations later, you won't have any problem, like TallStar said. The EP will install a new folder, 'Generations", under Programs/Electronic Arts/..... In that folder will go all the 'new junk' from the EP :-). Then, the EP Install Wizard will check the patch level of your Base Game. Since it will already be patched correctly, the process will end there.
Note 1: I'm under the impression that EA will release a lot of bug fixes with all the patches that'll come with Generations (so Base Game + all EP and SP). You might want to patch your other EP's or SP's too. I hope it's not a false impression because there has been some nasty bugs left behind for a long time.
Note 2: Like usual, it seems that those new patches bork CAW. Before installing anything, do a complete back up of all your CAW projects (the folder named "The Sims Create a Wolrd Tool" under [User Name]/Documents/Electronic Arts). Then, I guess we'll all have to download a new CAW again.
Note 3: I've just read on a site that can't be named here that there will be new freebies for players who upload memories to the Sims website or facebook. The good news for you is that the memory system is included in the Base Game patch. There are some nice stuff: barbecue, bookshelf, a hot tub (!!!!).
I think you have exams for the moment, right? Good luck with those!