So far, it seems that they've been at it for twenty years and have got to the the taxiing stage. They look like MR2s in the photos that I've seen. I always thought the MR3, with the tricycle undercarriage, was the best looking variant.
I'm not sure there would be the same level of public interest in a Shackleton as there would be in a Spitfire, a Lancaster or a Vulcan, despite my own clear preference for it in this case.
There was a really excellent video on YouTube, but it's gone 'private' lately, maybe it'll turn up again..