Whilst viewing the Willingdale Associates website (ref their plans for a new tidal barrier and road/rail tunnel under the Thames at Canvey http://www.metrotidal.com/) I spotted a project they call Waterloo Trilogy. This seems to be intended for the corner opposite the Old Vic (i.e. where the bookshop is) Go to http://www.willingale.com/Projects.html and click on the thumbnail picture that looks like a blue handled vegetable peeler. The 'peeler' bit will be the roof mounted wind turbines, somewhat similar to the 'razor' development at E&C.
They describe it as "a ground breaking 200-400 room sustainable hotel scheme at the heart of Waterloo".
This may just be speculative wishful thinking (a bit like the Canvey tunnel), but indicates further plans for tall buildings around Waterloo.
Sorry this is all I know - perhaps others can say more?
Although not a very realistic render of the proposed building (making it look as though it will be built of plastic) I welcome an addition like it. The current (ugly and old) building there needs to be replaced and although it is as you say another hotel...maybe it will prompt more interesting devlopments in the surrounding area in the near future.
It would be interesting to find out more plans for the area as Waterloo does have quite a bit of room left for modernising and updating.
It's interesting that you think Waterloo needs modernising and updating. Do you realise this generally means someone, somewhere will lose their homes. I live in a relatively small block of flats in Waterloo and so far we have had to fight off three developers who want to buy up the land (our garden) so they can build on it. The latest lot of developers want to knock the block (my home) down. Next time you walk down The Cut, look at all the red brick and old windows - this is history and adds to the character of Waterloo.