Sprint Mulling Switch to LTE and T-Mobile Merger

I think one thing that folks need to realize about going to "4G" is that it is going to take years for it to be deployed nationwide. Right now, every provider has to operate under a hybrid system between their new and old network. When everything is LTE we are all going to see better service, but that won't be for years. By then though, it will be blanketed over the US. CDMA and GSM won't matter after that and those older networks can be shut off completely. But again, that will take years.

By then, no one will own the EVO and you'll have switched to another phone. If for some reason someone is holding on to it, they will be forced to update their phone, but I don't imagine that being for another 3 or 4 years.