Code Secs. 72(t)(9) and 402©(10) [added by EGTRRA] will require a gov't 457 plan to separately account for any amounts rolled into it from a qualified plan, 403(B) or IRA in order to be able to identify those amounts subject to the 10% tax on early withdrawals. From what I can tell, there is not a comparable Code provision requiring the tracking of 457 dollars that are rolled to a qualified plan, etc. If not, then it seems as if those amounts would become subject to the 10% early withdrawal tax. Am I missing something here?

It is my understanding that assets that roll from a 457 plan take on the characteristics of the new plan. Assets that roll into a 457 plan retain the characteristics of the prior plan.

One thing that has come to light since I originally posted the question is some interesting language that was included in Notice 2001-57, which contained the EGTRRA good faith amendments. The IRS instructions relating the amendment for "Rollovers from Other Plans" state that "A plan that accepts rollovers may be required to separately account for such amounts." To my knowledge, this is not in any Code sections changed EGTRRA. So, it may be something of a "hint" from the IRS that its EGTRRA guidance will require that certain features from the "old" plan be tracked separately.