Nice to see someone using more yasnippet power! You might want to turn your snippet using gjg/move-next-sexp-past-current-scope into a snippet-command, something that is available in the yasnippet trunk, and will be released in the upcoming 0.7.

Have a look at this snippet

# -*- mode: snippet -*-
# type: command
# key: marcc
# contributor: Translated from TextMate Snippet
# name: Add / Remove Several Columns (marcc)
# condition: (yas/rails-intelligent-migration-snippet-condition-p)
# –
(yas/rails-intelligent-migration-snippet :add_remove_column_continue)

with the supporting code available at

http://yasnippet.googlecode.com/svn/trunk/extras/imported/rails-mode/.yas-setup.el

or mail me for suggestions. I’m happy to give you support, with what I can, and I encourage you to create more complex snippets or contribute to the textmate-snippet-conversion effort.

bye