To generate a cs file for your artifacts in BizTalk add the following to your registry
HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\7.1\BizTalkProject with a DWORD value named GenerateCSFiles – set the value to 1
Restart your IDE and that should be it .. 
Why would you want to do this? What are the benefits, if any, of generating *.cs files for your BTS artifacts?
Honest question, without any disrespect.
Keep up the good work.
Cheers.
Top question Brett
. Here was the scenarion I had to do it ..
I had an orchestration that was refering a map. Later for some reason I decided to rename my map (which was placed in another project). As soon as I changed all my references to point to the new map and compiled the solution – my orchestration project would break. It would complain about missing a reference to my old map.
Believe it or not – after generating my cs files for the orchestration artifact I spotted the old map reference. I did the traditional find + replace. Closed down visual studio, cleaned up all bin and obj directories and did a recompile. It worked !!
Sometimes, knowing about the product (BizTalk) hasn’t been enough. I had to think the Microsoft way (tweak n fix)
Brett – also very useful for debugging.
You can step through your Orch code – as messy as it may be, when you get compile errors that say line #1000…error:….. – you can go there and see what it’s about.
I’ve had many issues with expression shapes and C# comments in there – sometimes the IDE just screws up and inserts a plain piece of text such as “Object reference not found” (on a line all by itself). Remove the text and away we go.
It’s also useful to start to get a better picture of how Orchs are put together – their contexts and statemanagement.