Really? I thought he was just being polite! I was a bit bummed at his rejection (although I'm used to it) so I wasnt really up for another "oh yeah....sorry not my thing" type email from the same agent. I have considered it but my first novel is still being edited (on this very helpful website as a matter of fact)so it wouldnt be ready for another few weeks anyway. But I wouldnt have thought it was a positive sign, thats quite uplifting actually...kind of a miniscule step forward!
By the way, its really coincidental that you thought you were going to be rich and famous Colin-M, I imagined the exact same thing! I sent my first manuscript off at 14 and 1/2 years old, unedited with no margin and received it back three days later...I cried.
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"I’d certainly be pleased to see any other full length proposals you might generate in the future."
This is the exact sentence this agent used and I kept the email because of the comments he made.