What is there about 4G to not be keen on? (or rather...why would it be a deal breaker?) Sure, the network coverage for 4G could be sparse in some areas, however, it still has full 3G functionality and drastically improved data access where 4G is indeed available?
As I wrote earlier, I have iPad 1 and 2 and swap my unlimited 3G SIM between them. If I went to a 4G device, I'd lose that flexibility.