I went to a dealer nearby and he received a notification today, which includes the part numbers for the BMW Performance Power Kit.
Here they are:
11122157663 - for cars with MSD81 (US pricing: $2065)
11122157664 - for cars with MSD80 (US pricing: $2561)
There is also a number (I don't know if its a part number) for the installation instructions, but I didn't note it.
The kit will be available for 135i, 335i and 335xi. No 535i but it may be because this model is not available in Europe.
The power kit is almost ready to be ordered, it can already be ordered from Germany. The dealer said it should be in the ordering system in a few days...
Now I know where a good part of my next month's earnings will be gone...
Diagram of Performance Power Kit: