Singapore has joined the club:
A 20-30 % drop of residential property prices is now expected for 2009. This forecast assumes that the pace of decline will slow in Q2-Q4. I wouldn't bet on that, as Singapore's GDP will decline 5-10 % this year, most likely causing an exodus of foreigners, including many high-income expats.
Q1 was dismal: In just one quarter, prices dropped 14 % (in Q4, they already dropped 6 % from Q3, following a 2 % drop in Q3).
Sounds pretty nasty. But then, Singaporean property prices were sky-high at their peak in late 2007 / early 2008.
Oh, and rents for high-end apartments are down 19 % Q4 to Q1 - i.e. they've basically been falling off a cliff during the last 3 months.
(source here and here)