Being an old QA hack, I notice that the guarantees, good in themselves, come without defined *quality* standards.
While the implied standards would be 'Does the job' or similar statement, the lack of any specifics would make me (as a customer) quite uncomfortable. I can easily see an exaggerated situation where the software meets the startup requirements, but fails under additional use shortly thereafter.
So how does a customer specify quality and performance requirements, and how does the vendor verify that such requirements are met?
Delivery guarantees are a good start, but I'd be happier with a quality guarantee and worry less about slipped delivery. Late deliveries can be lived with, up to a point, but poor quality on an operational system can be a disaster.
Let's make sure we have the emphasis on the right component.