When 4G (LTE) Networks roll out for the public in the uk we will write mid 2013 or even beginning of 2014, one, or even two iPad revisions from now. And you will not like it. I see the plans they offer in parts of Germany, here in Spain and the ideas Vodafone and others have in the uk.
The networks are going to have a theoretical maximum of 100Mb, but nobody, I mean nobody, is going to get that. In Germany in practice (I did try with a LTE USB Stick) you get "up to" 50 Mb with rediculous short cut off points (5,10 or 20 Gb) before being throttled to 386kb. The whole thing with prices that are more 90s then today.
In practice you get real 30-35Mbs down. So, depending on your cut off point, you have a few minutes to half an hour a month and you are done. Also, you can not move around, they have an experimental handover on the 20 Mbs tariff, but it usually is not working, also, the coverted areas are so small, that driving in a train gets you 5-10 mins max coverage on a hour trip.
On the other hand you got the 3G Network, very well build up, download speeds of "up to" 42 Mbs, in practice around 30-35Mbs. The same then LTE. But, no throttle, funktioning handover, and half the price. More important, WAY less battery use, extreem quick hook up and with ping times as low as 40ms even usable for casual gamers. I have 3G coverage everywhere in my house, the office and everywhere in between. The LTE stops at the first wall, no penetration at all, its really useless. It is also marketed not for mobile use (the proposed speeds make no sense anyway on a iPad, phone or what ever) but as DSL replacement, stationary at home. They put a small Antenna on your roof and you get fast internet when no DSL lines are available.
So, why are some people here so hot for LTE? in the states I can understand it, any one that knows European networks and "experiences" fe AT&T offerings will understand that something has to be done. It really, well, its not good......
But here in Europe LTE is a LONG way off before it can get any headway against the existing and still improving 3G Networks. If the new iPad would support european LTE AND 3G, the LTE part would be the first thing I disconnect.