For the record, I'd sharply dispute that your question title “more or less says it all.” The better preposition would depend on the nature of the project, and the nature of the prospects as well (which may explain why the Google Fight you linked to was such a close match). It's context dependent; you haven't furnished enough information by asking us to choose between the very vague "Prospects of Project X," or "Prospects for Project X."
What might be the ultimate result of these new discoveries? Will they:
- Solve a nation's energy crisis?
- Help a law firm win a case?
- Expand the customer base of a manufacturing plant?
- Cause fourth quarter profits to rise sharply?
- Make a dangerous machine more safe to operate?
- Eradicate or cure a
I might decide to use a different preposition, depending on what prospects are being presented, and how those might be discussed.
Macmillan and Collins both list several definitions for prospect, each with a slightly different nuance of meaning:
(a) something that you expect or know is going to happen in the future, or the thought of this
(b) something hoped for or expected; anticipated outcome
(c) ([usually pl.]) apparent chance for success
(d) the possibility that something will happen, especially something good
Interestingly enough, the last one I listed comes with two usage examples in Macmillan, one using each of the two prepositions you inquired about:
prospect for: The prospects for employment in the technology sector are especially good right now.
prospect of: Doctors say there is little prospect of any improvement in his condition.
So, to show how this can be context-dependent:
Project X: find a more streamlined manufacturing process for making widgets
Potential Discovery: a cheaper way to make widgets
Repercussions: higher profits, or greater market share due to lowered prices
My Presentation Title: Prospects for Streamlining Widget Manufacturing
Why: By "prospects" here, I'm referring to the optimism that the process can be improved [meaning (b) above]; for seems to be the better fit.
Example Paraphrase: Our prospects for improving the manufacturing process look good.
On the other hand:
Project X: find a cure for toe cancer
Protential Discovery: a cure
Repercussions: new advances in medicine
My Presentation Title: Prospects of Finding a Cure for Toe Cancer
Why: By "prospects" here, I'm referring to the likelihood that a cure can be found [meaning (c) above]; of seems to be the better fit.
Example Paraphrase: The prospects of finding a cure are slim.