The new kid on the n-tier layer block?

Is WF the new kid on the block when it comes to designing data-driven n-tiered application?

I'm

not sure but I'm testing the water a bit this week and besides a few

teething problems this looks a great foundation to address one of that

last bastions of application development - creating re-usable "business

processes".

However, I'm still a little foggy as to how I should actually go about designing when it comes to which layer should do what.

I have a UI, Business, DAL and Server structure - very typical

For example the UI populates business entities and the business entities do the Save() and so on ...

Now how

does WF fit in here? Should WF become involved in persistence? or

should it just take care of Activities that linger on the peripherals

of the CRUD work?

If I'm updating objects that have various states, and depending on the

state it has, cetain activities happen - it's pretty nice to have

statemachine doing some of the desicsions for you...should it do more

that just the activites - should it do the crud as well? - I'm not

sure.

Nothing is

really as straight forward as Sample apps, and I never expect it to be,

but still I'd be very interested in anyone else's thoughts on how

they'd go about fitting the 'new kid in the block' in.