I just had a call with the always-interesting Actix, which provides planning and optimisation tools for 3G networks. They're enthusiastic about LTE, commenting on its ability to lower the costs of mobile broadband provision compared to alternatives like HSPA+.
Certainly, some operators appear to agree - T-Mobile is cited as being an advocate of leapfrogging HSPA+ and going for early LTE deployment. Others like AT&T and Telstra are more enthusiastic about HSPA+ .
(Yes, officially it's called HSPA Evolved, but everyone I speak to outside Ericsson thinks that HSPA+ is a snappier term).
For the LTE enthusiasts, one of the prime attractions is lower cost-per-MB for data compared to HSPA, especially important given the price and use curves of 3G in notebooks and smartphones. There's even a suggestion that they might switch off UMTS 3G networks before turning off voice-optimised 2G GSM.
If that's really the case, I would have thought that having a long-lasting legacy of devices only using the older, more expensive network technology would be undesirable - you wouldn't be able to transition their traffic to the more efficient LTE until much later. Now phones have a natural lifecycle of a year or two, especially at the high end. But notebooks endure much longer.
If you're rolling out LTE as early as you can, do you really want a load of HSPA-embedded notebooks and other devices lingering around on your older network for 4-5 years?
[I suppose you could just give these people an extra LTE dongle nearer the time, although that may mean having 2 SIMs in the notebook operational simultaneously if they don't remove the embedded one].