io9 has a bunch of interesting rumors about Transformers 2. Warning, though unconfirmed, these COULD BE
spoilers so don't say we didn't warn you!
Here is one:
More spoilers from an anonymous source. Apparently, Arcee, the female Transformer, doesn't die in the movie — instead, she doesn't show up until later on, and she spends most of her time in robot form instead of her three-motorcycles version. Only one character combines with an Autobot to make a bigger robot. The Constructicon is nine vehicles put together, but it'll only put in a brief appearance. Scorponok is back, and he uses his internal "spark" to restore life to one of the Decepticons. (Gosh, which one could it be?)
There's also this nugget:
And finally, "the Fallen" is an old Cybertronian legend — it's not one robot but a whole army of robots who are supposed to protect the Cube. When Sam goes bonkers and starts talking gibberish, he's actually reciting Cybertronian hieroglyphics prophesying the return of the Fallen.
You can check here
for more rumors about Transformers 2 as well as Quantum of Solace and some TV shows.