Re: [ANN] KRAKEN.COM - Exchange Now Open with USD, EUR, BTC, LTC, XRP, NMC, XDG
I believe i have read that kraken allows margin trading now. I cant find where to trade with leverage though.
"soon" 
https://bitcointalk.org/index.php?topic=290799.msg10672861#msg10672861
It's been "soon" since post 1 in this thread...
Services that appeared in Beta that are not available at launch:
GBP pairs
Margin trading
If all goes according to plan (as usual), well reintroduce these services within 1 month.
GBP pairs
Margin trading
If all goes according to plan (as usual), well reintroduce these services within 1 month.