Not any time soon. For starters 4G is not really available yet (i.e. there are no devices (towers or cells) that meet the actual standards of "4G." What Sprint is calling 4G really isn't (and falls WAY short of the actual accepted 4G standards). Sprint has had to resort to this for marketing purposes (essentially it's a 'hail mary' marketing attempt to bring them market share). The current time-frame for production of LTE-A devices (still a pre-4G tech not true 4G is not until at least 2011).
Even after the technology is in place (i.e. developers can make the devices) there are a LOT of MAJOR things they have to have in place before they can even think about implementing it. First above all they need a LOTTTT of devices (we're talking 10,000s of modules to put onto their towers). Then they need the manpower to update all their towers.... and on and on.
If your interested:
4G - Wikipedia, the free encyclopedia
I've been trying to say that for awhile... so +1 for you.
Secondly verizon techs and others i've talked to in the verizon ranks have stated the time frame of 2010-2013. They said most likely with first implementation around the end of 2010, which is ONLY for users who have aircards, and devices of the like. So cell phone users won't see a 4g network on verizon until 2011 at the earliest, unless they are ahead of schedule. So far i haven't seen any phone from verizon that offer 4g yet so, they will have to roll those out, you should see these come out shortly before they "plan" to implement the 4g.