Despite the issues Motorola had with phones in the nineties/naughties, you think they were sitting on their hands doing nothing? They've had a very active innovation culture which continues to this day (albeit on a smaller scale now). The essential patents count for not much, as they have to be licensed on a FRAND basis - at which point it's a question of "whose pile is the biggest" influencing the cross-licensing revenues, but they had a variety of all sorts of clever stuff going on - even innovating around the styling of the phone (StarTac, RAZR, etc..).
Also, from my recollection, the balance of revenues from patents was greatly in favour of the mobile division versus the networks division (where I was for 10+ years) - probably as a consequence of the FRAND stuff, but I never saw an analysis.
It will be interesting to see if Google change the standardisation strategy of MotoMob.
Oh and, for reference, GSM is still alive and kicking (VAMOS, REDHOT & HUGE (don't put engineers in charge of acronyms) are rather recent features, and I've been out of the loop for a little while), and Motorola Mobility is still involved in shaping the standards. GSM did not stop innovating in 1990.