Charlie Jeff and others have mentioned that Duet has miffed off some of the folks from Microsoft business systems (see here). Any significant alliance is going to upset part of a big business.
Oracle Application presales guys get really upset because more SAP applications run on Oracle databases than do Oracle applications.
At SAP we have a lot of discussions about how Duet and the Portal work together and overlap. The guys who built the calendar feature in the SAP portal probably don't like Duet either. I dont think we have all the answers yet.
For me, the interesting thing about Duet is not the product.
Okay, Yes, it does all that bringing SAP apps to the familiar desktop of the user etc, but Outlook has been arounds for aeons. SAP has been doing employee self service since the mid 1990s, we have sold over 13 million ESS users.
What is interesting to me,
1. It is a joint development. SAP developers and Microsoft developers working on the same product, together. In joint teams. SAP's dev lead on this is one of our best.
2. It will be sold and marketed by both companies.
The second point here is going to be key. How will we and Microsoft go to market, how will the Microsoft salesforce line up behind Duet? In the "early" accounts where I have been involved, I've seen strong colaboration between MSFT and SAP teams.
If I was a top sales guy at MSFT, what would I rather be selling
Vendorprisey 
Good point all depends on the commision the microsoft sales guys will be given to push Duet.
To a point. you dont get commission if it doesnt sell though. Salespeople are very good at finding out what sells and selling that. Even with the best commission plans, products that the market doesnt want dont sell.
If it was only about commission Oracle would be walking all over the market.
Cannot agree with you there, Thomas, about THE most important thing of Duet being that it is a joint product of Microsoft and SAP. That certainly is important for sales folks at SAP and Microsoft – but, I think customers do not care as much about “who” brings value, but what “is” the value.
Duet is receiving good customer feedback at this time because it is doing what customers have wanted for a long, long time – an ability to interact with ERP system in their familiar interface.
At this time, the “new-way-of-doing-things” value for Duet is high, but wait till it is deployed and used for a while. The shortcomings of Duet, -about it being able to talk to only a single back-end, SAP, about being able to talk to only those SAP transactions that have been value-packed, about the kind of upgrade it needs – could seriously make customers stop and hunt for extensible alternatives.
– Sangeeta