Another topic which IMHO would do the Haskell community a tremendous deed is auto-generating forms (in the sense of data entry systems) for Generic data types. For a thesis, this would mean to (1) flesh out what exactly characterizes a form [*], and (2) provide some proof-of-concept implementations for various form incarnations, e.g. HTML forms.
An implementation that works for IO as the form monad can be found here.
Other functional languages like Clean have these.
[*] If we allow recursive, possibly infinite types, then forms must be dynamic and possibly stateful. For systems like HTML one must be able to attach unique identifiers to every input field of a form, otherwise marshalling the posted data into Haskell would be impossible.