Right, but you can write AddIns in Python for ArcMap now, so that's why I asked. For me, at least, coding in Python tends to be more intuitive than .NET. But perhaps i just have to knuckle down and learn some .NET! ;>)
I agree that it would be nice to have python add-ins in Pro (since I have them already written for desktop), and I'm holding out for them adding the functionality in the future. Part of the issue will be with Pro having the "ribbon" style so they would have to figure out how we can access that interface.
One workaround is that you can still access and run the tools if they are in a custom toolbox. So, if you connect/add that to the new "catalog" in Pro, it should still work (pending any other changes that need to be made to the code for the Python 3.4). Not a perfect solution, but at least for me the programming and organization part isn't wasted. And for me, at least on some initial test (a while back in beta...before Python 3.4) the speed performance was so much faster with the 64-bit Pro that for some of my processes, I will live with it.
Starting at ArcGIS Pro 1.2 you can create and add Add-ins to Pro as a new tab. I used Visual Studio 2013 with the Pro SDK.
If you click on the Project tab in ArcGIS Pro you will now see a link to the #Add-In Manager. This page shows the currently installed add-ins in your c:\users\<your user id>\documents\ArcGIS\AddIns\ArcGISPro folder. To add additional locations Click the 'Options' folder. The paths entered here available in other projects opened by the same user. By default the path is saved to HKEY_CU\Software\ESRI\ArcGISPro\Settings\Add-Folders instead of HEKY_LOCAL_MACHINE. However, you can export this key from the registry and update it, and import it into HEKY_LOCAL_MACHINE. Now the add-ins located at the designated folder will be shown under Shared Add-Ins area in the ArcGIS Pro interface. When doing this ensure the folder you use is public -such as C:\\ProgramData\\<your addin name> or C:\Users\All Users\<your addin name>. This is where your would deploy your application too.
Rich D., GISP