Yesod is still missing a model layer. This is a project that I will most likely be doing myself, since it will need to be designed to integrate very closely with Yesod, but I'll mention some of the design ideas here. (By the way, Chris Eidhof has a package on Github called Basil which looks very interesting here.)
1) I want to use YAML quasi-quoting to define the models.
2) I don't want a super-complex "object relational mapping"; Haskell is already much closer to the relational level than an OO language.
3) Utilize IO thunks (ie, lazy IO loading) so that we don't need to load everything into memory at the beginning.
4) Not tied down to SQL *or* in-memory databases. It should support both of those, but *also* support a system that is usable even in a CGI setup. I'm contemplating now a database that uses multiple directories/files and uses append-only to avoid concurrency issues.
Compile-time checking of templates would be great. The Bravo package looks interesting, but I'm a little dubious about the approach used. I think something based on typeclasses might be a bit more nimble. Once again, tight integration with the model system I theoretically design would be nice.
So, in summary of a much-too-long e-mail, let's not bother trying to get everyone to agree on One Framework. Happs has its place, Yesod has its place, and I know others are using Loli and probably Kibro. (I'm not sure if anyone every got started with Turbinado.) However, we can raise the bar for *all* packages simultaneously by making a more solid ecosystem of Haskell web packages available that any framework can cherry-pick from.