Silverlight - modularity. Best way to physically separate binaries?

Question

We are working on LoB app with lot's of content. XAP download will be rather large I think for one time download. I'm planning to break solution into separate projects.

Not sure why - but I DO NOT like many many projects in solution. IMO it is not very good idea. Even when we were working as a large team - it was pain with many projects.

Even now when I'm using MEF/PRISM - there still going to be some core dependencies like:

1. PRISM libraries
2. Interfaces
3. Navigation
4. Shell/Bootstrapper
5. App styles
6. Converters/Commands/Validators
7. etc.

And than I'm going to have modules that will use all that CORE stuff. Modules will have following inside them:

1. RIA Services client side
2. ViewModel's
3. Views

Those modules will be loaded on demand using MEF. I think size-wise all those modules will be larger than core module because of ammount of logic in them.

I expect to have about 5-6 modules and CORE. I think that will give me reasonable number of client-side projects and libraries/XAPS and it will be manageable solution to work with.

Do you see any issue with breakdown like this? Some online videos will make 7+ projects out of CORE module. What's a point? I think it adds to complexity. Than they show 3-4 DLL out of module. One for views, one for viewmodels and so on. They still need to be loaded together so why?

I'm looking for do's and dont's from you guys who went through this..

Thank you!