Well, I started off on a simple task of creating a test WCF service hosted in a windows service that was secured by https and was compatible with older clients.
Here were my hurdles. I'll come back and post links to each step.
1) Getting a WCF Service Working
2) Getting a Windows Service Working
3) Getting my WCF service class working in a Windows Service
4) Getting SSL working
5) Getting basicHTTBinding anonymous username/password working
Here is where I started running into trouble
6) Getting XML enums to serialize correctly in WCF.
7) Possibly needing to flatten WSDL files
8) WCF clients can connect to the mex and discover the service, but displaying the description or the WSDL in a web browser returns 400 or 415 errors (could be related to #7).
So, I decided at least for now to say "f it" and drop the project. Instead I will use an ASMX old school service hosted on IIS.
So far the WSDL issues went away, the challenge will be testing SSL (since I don't have IIS running on my box). I will give myself bonus points if I get the ASMX service working with SSL in a Windows Service, but that is a low priority at this point as time is a'wasting. I get super bonus points when if I'm done and have any time left, I can circle back and get the WCF working.
The lesson here? WCF is great...going forward. If any part of your tech lies in the "legacy" realm, <sarcasm>like Java or non MS clients </sarcasim> don't listen to all the folks towting how great WCF is and how it is backwards compatible, go ASMX.