Can't speak for the fens, but we've certainly not had any flooding in the Brecks (I live in Thetford), the soil here is very sandy so even the day after heavy rain, which we have had, the ground is bone dry.
On a birding front, some of the local specialities are getting more difficult to get to grips with now. As far as I know the cranes are still around at lakenheath as are the Orioles, but not as obvious as a few weeks ago, but Hobby should be seen easily enough. Weeting will certainly be worth visiting, the Stone Curlews should be obvious and starting to gather, and can be a lot closer to the hides. Just about any forest clearing at dusk will have churring Nightjars and Woodcock, and during the day, keep a look out for family parties of Siskin, Crossbills and Firecrests.
Not sure about flooding - but I'd recommend a couple of stops on the way there - Welbeck Viewpoint near Clumber Park - pretty reliable for Osprey, Honey Buzzard and Turtle Dove at present, amd Digby Fen for the Montagu's Harrier which have 4 young on the wing at present, and a nearby Black Kite for good measure!
I'm off to Ely next week and hope to visit Lakenheath (anyone know if the Cranes are still there ?), Weeting Heath, Wicken Fen and Welney - and Ely cathedral, some tea rooms and other such non-birding activitties to keep the missus quiet.
Anyone know if they have had flooding down there or any other handy birding hotspots ?