HTC just announced on their site that they will reveal a new 4G capable handset on January 6th, leading to rumors that the handset to be announced is the HTC Thunder (previously known as the Droid Incredible HD and Mecha), due to the timing of the announcement, as well as the text in image, saying that this handset will be "the first to 4G, again."
Since the HTC EVO 4G was the first handset to "4G", if they are going to proclaim their new handset will be the first to 4G, it would have to be a signifcant increase in technology, which seems to indicate they are talking about LTE, Verizon's 4G network.
The timing of the smartphone announcement coincides with a press conference by Verizon at CES on the 6th. Adding to the clues is the fact that the HTC Thunder/Droid Incredible HD/Mecha was previously seen with built-in 4G support.
The HTC Thunder will likely not be the first LTE handset on Verizon for very long, as apparently an LTE version of the Motorola Olympus is in the works, as well as an LTE-capable phone from Samsung.
Internal specs will likely be very similar to the Desire HD that launched earlier this year, except of course for the addition of LTE capability.
Check out the announcement page for the phone here.
Image from AndroidandMe