Help on specifics of restraint clauses of Service agreement

Due to unavoidable circumstances, the contract between my current company XYZ and my client company is going to end on 31st Dec 2009 and its not going to renew in future.

The problem is that my current company is not ready to leave me and is stating that it will put legal allegations on me or ABC company if I join the client company after 31st Dec 2009.

I have a service agreement signed with my current company that I cannot join any client and competitor after 1 year of my voluntary exit i.e. a "Cooling Off" period of 1 year.

I am aware that these kind of agreements are in place to avoid employees to jump directly to client companies or compitetors.

However in this exceptional case, where after 31st Dec 2009, the client-partner relationship itself is not going to be in place, what are the chances of my current company XYZ to win a case if they take legal action against me or ABC company if I join ABC company.

Also its noteworthy that:

1) I have no such confidential information to be shared with my next employer which can be used against my current employer in future as I'm into support kind of a role.
2) There is no mention of ceasing of contract condition in my Service agreement.