How do I convert an extension containing a MapControl to ArcGIS 10?

[WilliamKirchhoff]

I created an extension to ArcMap (9.3.1) that employs a MapControl.  I recently upgraded to ArcGIS Desktop 10 and found to my dismay that the MapControl - which resides in ESRI.ArcGIS.Controls library - now requires an Engine license.  Setting aside my deep displeasure at this change in marketing strategy, my operative question is - how much do I have to spend to enable the MapControl so that I can upgrade my extension to run in ArcMap?
I have had several conversations with ESRI's sales & marketing people and I'm still confused.  It appears that if I purchase an EDN subscription I will receive the ArcGIS Engine SDK and I should be able to convert my 9.3.1 extension to 10.0.   My problem is that the ESRI folks keep talking about "production level" licenses - assuming, I guess, that they think I am trying to create a stand alone app that will be available over the web.  But, my program is an extension to ArcMap and will only be used within that environment - therefore the user has a ArcGIS Desktop license and should not need any additional licensing run to run my extension with its embedded MapControl?
I would appreciate hearing from anyone who has had to convert a MapControl bearing tool, command or extension from 9.3.x to 10 and what it took license wise to make it work.
Thanks.

[AlexanderGray]

Ok, I decided to activate my license before something broke and the manure hit the fan because I was scrambling to find the license codes and authorize them.
Right click on the activeX control on the map (you need the license to do this) select properties and you get this
[ATTACH=CONFIG]11341[/ATTACH]

[AllanMills]

Ah, thanks. I didn't realise it has a popup properties window.

Hmm, my preview option was already unchecked though - but I got an error when trying to run it a different machine. I'll have to investigate.

Thanks again.

[AlexanderGray]

I am running SP2, SP3 had some bugs with the label rotation so I held it back.