I am another one of those with a drop from Platinum, but unlike others I went down to Club, not unexpected but like everyone else here the card says EXP 2014, and I received a brochure with the letter, I think I may have thrown away the letter but I still have the brochure telling us how good Platinum is, I will keep looking for the letter but I don't like my chances.
What surprises me is that Hilton at least runs your status through to 31 March 2014, good for them, as I do about 10-20 hotel stays a year not a lot by FT standards but a bit of status will sway my choice of hotel. Hilton Gold and above got you free breakfast and now free wifi, PC platinum relatively easy to get but no extra benefits.