My experience shows that AGILE is, right now, the new “cool” marketing tool for sales people, at least for IT service company. 
And for me it’s just the beginning. That’s reminded me the IT offshoring concept : A great sales tools with huge economic gains , and a real nightmare for the delivery.
And if competition lead to fixed priced engagement, what is your competitive advantage then ? 
For me adopting an AGILE process have to be decided and communicate by the highest sponsors in the organization and not stay at the geek level…
and some time we disregard ( or we are not able to do )  this hight level communication  ( Procurement, Ceo … ) then we enter in the nightmare of the bribe,
cajole, lie and chit things…

Yes IT company have to make strong commitment… and for the moment I see two  guardrails  ( only if we have the right sponsors ) within the organization :
The benefice of a real integrated team Customer / Provider and the share  definition of the role and responsibility of the product owner.
Product Owner IS the key :) 

Amor Fati…

Cédric