Dragoneye,
The Bondholders hold 27 Billion of debt and the Government and GM want them to accept 9 Billion in Equity and eat the other 18 Billion. The guys holding the Bonds are "Playing Chicken" and will not agree as they don't believe Congress will let GM file for Chapter 11. If GM did file for Chapter 11 and it resulted in a "fire sale" and liquidation then they would be at the top to receive any cash generated by the courts. I think some estimates are that they could get nearly that much from the sale of GM and its' components but I doubt that.
At this point the only thing that would get them to agree to such a bad deal would be the threat that they will lose it all or most of it if GM goes belly Up.
The UAW has made concessions for current workers but the retiree legacy costs have not really been dealt with and could be fairly reduced in many ways like terminating medical coverage at 65 and increasing monthly premiums. The UAW is not really coming around because they believe they have the support of Congress.
Like I said before, Chapter 11 would have already happened if Congress were not holding it up. However at some point I think Congress will have to back off and support a GM Chapter 11 filing (at least in appearance). As soon as GM makes an announcement that they are going Chapter 11 and Congress openly supports it and says there is no other option, watch how fast the UAW and the Creditors start making deals.
If Congress makes a back room deal with everyone to go Chapter 11 without the needed concessions and sets up a tax payer debtor financing package thru a puppet bank then the whole thing will be doomed to failure because GM will simply keep burning thru the cash and ultimately collapse taking all of our money with it. Congress has already stated that they will only assist if GM agrees to put a hold on future employment cuts and plant closings and protect the jobs of the UAW workers.
The "Committee" that is working with GM has no real authority and is a smoke screen to provide cover for Obama and Congress.
The future of GM depends entirely on whether Congress will do the right thing and let them do an honest Chapter 11 If not then I don't think they have much of a chance with their business being hamstrung without the needed concessions.
GM should never have taken the first dime, now they have been prostituted and have no control of their future.
BS Disclaimer
(The above is my opinion and may be seriously flawed and inaccurate.)
Steve