Descarte isn't in the least vindicated. Even if you could prove your "pondering" exists, which you can't,
Sure I can. The fact that it is taking place proves it exists.
why is there any particular reason to believe it is your pondering? Why can't all the manifestations of your pondering that you find so manifestly proving your existence, be the result of some superior being who dreamed you up, complete with your conviction that it must be you who exist, because of your illusion that you are thinking stuff up.
Again, this misses the point. As I clearly wrote above, WHATEVER ITS SUBSTRATE might be -- including any variation on "dream within a dream of a superior being", the fact that thinking is taking place proves the existence of the thinker (i.e. that which thinks). Decartes 1, you 0.
Since you are willing to accept your pondering's supposed existence without proof,
Faulty premise, nice try.
why should I regard the notion that some being thought you and your ponderings (or me and my ponderings) up as any less reliable?
Conclusion based on faulty premise, therefore the conclusion is faulty.
Nonsense. There ain't no proof of nothing here. Descartes' claim is an assumption based on faith. The nature of a proof, whatever else it might be, is that it is something the other supposed entities in the world might verify. Your inchoate perceptions are not of that nature, they are exclusively yours--and things only you can perceive are only perceived, much less proved, by you; not to put too fine a point on it.
Not that it's terribly relevant, but you have not demonstrated that an hypothesis is wrong, just because you find a flaw in it's proof.