I've just put build 153 to our download storage. Ugh... It includes new refactoring called "Introduce Parameter" and I spent the whole last week implementing it. The idea is simple: you take a variable or an expression, invoke the refactoring and it adds new parameter to your method/constructor/indexer signature and initialises it with the selected expression or variable initializer at all call sites.
But of course there are lot of details: dealing with params modifier, qualified calls, usages of other parameters, etc. Of couse there are quite a few tests on it, but if you find a bug, please report it to our Tracker.
I also added slight modification to the "Extract Interface" refactoring to support so called "quasi supermembers" ;). This is our internal name for the case when an interface member is implemented using base class' public members. So now you can select such members for extraction.