mde's layout system with its ContentBox? etc. seems to me redundant - it's another widget system.
doesn't keep a handle on the widgets, just the widget dom nodes (see for example layout.js handling of CollectionSelector?)
CollectionSelector
fillInTemplate is a nightmare. WAY too long, too many functions defined inside that function
uses closures like global variables with short names. Hard to find where they where set. Difficult to refactor because of all the closures. Bad encapsulation
cosmo.app.showErr
don't really like passing the error as an arg...unless using kwArgs...something icky, can't place finger on what.