LOL! If there are 10,000 SL developers, there have to be 15,000 reference apps for SL4 + MVVM ;-)
More seriously, there cannot be such a thing. The business needs and developer environment have more to say about the "right architecture" than any one reference app.
Wish I could do better than say "it depends".
Perhaps this is a littel better ... a small set of reference apps that I think could inspire you:
Exhibit A: For DevForce, the closest we have is
PrismExplorer. It targets composite applications and is intended to illustrate that DevForce and Prism play well together. Two words of warning: (1) those twin goals mean the concept count is higher than you might like ... and higher than is necessary to bring off a S+ MVVM app and (2) it's old ... two years? ... and our thinking has evolved.
Exhibit B:
Laurent Bugnion, author of
MVVM-Lite, is a wise soul who is striving to make MVVM accessible to all. I'm eagerly anticipating his "Silverlight 4 Unleashed" which I expect will walk you through MVVM. We're looking forward to doing a DevForce + MVVM sample app ... not sure when though ... and open to contribution from the community.
Exhibit C: Investigate
Caliburn.Micro . I like it. It's very programmer-oriented and not terribly Blend friendly but wow is it productive. You do have to get over the concept count ... it's not for everyone ... but it is powerful, elegant and "simple" once you get the hang of it. I'm hoping we'll have a nice example of DevForce + Caliburn, written by the author of Caliburn, in the "near future".
Exhibit D: The Stockbroker reference application for
Prism v.2.2 No DevForce in it but lots of ideas. Warning: this is more than 2 years old ... I'd be tempted to peek into the (near) future and look at ...
I believe Exhibit B is likely to be the easiest; I say that even as I must confess that it is the only one of the bunch that I haven't personally used ... YET. Why do I recommend it? Because it has a sterling reputation and I know Laurent well enough - we've had many happy and productive discussions - that I'm 100% confident in his guidance.
HTH
Edited by WardBell - 30-Aug-2010 at 1:13pm