According to Wikipedia, “HSPA+ provides HSPA data rates up to 56 Mbit/s on the downlink and 22 Mbit/s on the uplink with MIMO technologies and higher order modulation (64QAM)“
Telcos just need to perform a simple software upgrade to enable HSPA+. Of course before doing that, they need to spend at least a few million to upgrade backend/backhaul and also bring in HSPA+ supported devices.
If you ask me when will this happen? Probably end of next year.