I was last in Cuba in spring 2009
It is changing rapidly. When I first visited in 2001 the majority of the cars on the streets of Havana were 1950's and their condition was good. There are many more cars now and most of them are modern. Of the dozen best photographs i took in 2001 not one could be recreated in 2009 as a function of demolition and restoration. There comes a point that between atmospherically derelict and downright wrecked where thing tend to lose their charm. Standards of hotel accommodation and food have improved- and whilst I wouldn't even now go to Cuba for luxury its not today a place where its really difficult to get palatable food. There are a lot more signs of commerce and private enterprise, partly to meet the opportunity presented by the hordes visiting the "all inclusives" on both coasts and who get tempted onto coach trips to see the "real Cuba" for a few hours. Havana is outside the restored tourist core a pretty dirty city now- clearly the money's running out and things like refuse collection don't happen as aften as they should and in places its unattractively smelly wich wasn't the case in my firsy few visits. All that's why the state is turning a blind eye to Paradores, to private tourism ventures and so on- the fact is they've had to subcontract the responsibility back to the people. In places like Trinidad there are now street markets where just a few years ago there was nothing to sell - and few people who could buy anything.
I guess if I were from the USA ( and I'm not) I'd be thinking about how to get valid insurance cover when I'm not supposed to be there; things like repatriation in the event of sickness might be quite interesting for example; reassurance that they won't stamp my passport, and I'd also be thinking about the fact that there may be lots of doctors but they don't have ready access to a lot of the things ( like antibiotics) to cure relatively simple things quickly. If I went I'd be going on the understanding that the inland scenery isn't great and the coastal scenery isn't anything you can't get anywhere else. But the towns, cities, villages, people--well that's different. For people on a short trip with others these risk and inconveniences might well be acceptable. I've been alone without any spanish and coped.
Photographically, IMO Cuba is not as good as it was, but its still very interesting. The rate of observed change tells me that its isn't something that can be left for the next ten years unless you want an entirely different type of experience.