I'm not sure exactly what arguments 2 and 3 are.
I think his three arguments are as follows:
Argument 1: superintelligent AI is unlikely, because human-level AI (a necessary step on the path) is unlikely, because that isn't really what people want (they want more tightly-focused problem solvers) and because there will be regulatory roadblocks on account of ethical concerns; and if we do make human-level AI we'll probably give it goal structures that make it not want to improve itself recursively.
Argument 2: mind-uploading is unlikely, because lots of people will argue against it for quasi-theological reas...
I periodically get email from folks who, having read "Accelerando", assume I am some kind of fire-breathing extropian zealot who believes in the imminence of the singularity, the uploading of the libertarians, and the rapture of the nerds. I find this mildly distressing, and so I think it's time to set the record straight and say what I really think.
Short version: Santa Claus doesn't exist.
- Charles Stross, Three arguments against the singularity, 2011-06-22
EDITED TO ADD: don't get your hopes up, this is pretty weak stuff.