The bit about RTD doing Doctor Who in the US while SM does Doctor Who in the UK sounds like something the writer just threw in there. I don't buy it for moment.
As for remaking Torchwood in the US ... I could see that happening. Won't last more than a year or one and half <g> but it could make sense that Torchwood, taking a more global view again, opens offices in other countries.
Any US version is likely to pale quite a bit in comparison with Children of Earth, which was a fantastic piece ... but if RTD is actually doing season 1(series 1) of Torchwood over again - well, it's not like anyone could do a worse job than the original crew. That was a low as those stories could go.
I think RTD would love a chance to fix up Torchwood - and we've already seen with Children of Earth what he could do with the dismal start it was given(tho it was definately improving the second year) and despite our expectations, brought it up to the level of a decent drama that could wrench an audience and cause debates on morals at multiple levels ... it might be fun to see him tackle that year and give us the season 1 story level he wanted to start at.
If it actually makes it to the TV, this is the one retake I would actually look forward to.