I don't know. I think it depends on the terms of the agreement; however, typically companies coming out of Chapter 11 don't make good investments.
Factors to consider:
1) Senior Debentures should receive 23-27 cents on the dollar (or less)
2) Assets should be at least 25% higher than total liabilities; it is preferable when it is 2:1.
3) Management should be completely changed.
4) Existing shareholders, preferreds, and subordinated debentures should receiving nothing.
5) Cash-flows from operating activities shall be positive.
If those three factors are met, it is possible that GM could be a good investment; however, if not ALL three factors occur, don't buy the new GM shares. One thing that makes tech companies so popular is that many of them have cash + short-term investments > total liabilities.