as a skilled AS3 developer I wonder if there is something like AS3 to JS migration guide. After all both languages have a lot in common.
I have in mind something like the old AS2 to AS3 migration guide - a list where I could simply look up the AS3 functionality and the JS counterpart, or vice versa.
I am not saying you can easily convert all your code like that but it would tell me where to start.
PS: I think it is a great idea and if such guide doesn't exist someone should write one :).
You're going to have a difficult time of this considering a lot of the flash.* packages don't have any native JavaScript counterparts. Maybe a robust JavaScript library can ease the transition, but there will be a lot not migrate-able.
However, many of the Top-level datatypes do have a JavaScript counterpart (i.e; Date, Array, String, Object, null, Number/Integer)