So yes, this upgrade is still coming. The N54 turbo upgrade market continues to heat up and really the main thing it is missing with a single turbo option out (kind of, still being tweaked and no real info from the handful of customers who have it) is an option for upgraded larger twins. For now, the only twin upgrades have been to the stock turbos.
There is no timeline of completion but it looks as if CP-E and Vargas Turbocharger Technology will have the main turbo upgrade options for larger twins on the N54. Expect debate on the forums to soon shift from which tune to get to which turbo upgrade to get. Let the single versus twin debate begin!