Moblin actually did have a rep. at the time (for some form-factors) when it comes to Linux.
I recall several extensive writes-up from sites like phoronix that felt it stood-out from anything else around at the time.
This was before the tie-up....
It did have some good stuff to bring to the table, I can't recall it all now, pretty sure power management was part of it.

But I guess most of the good stuff it was to bring was really for diff. form-factors.
Or x86 smartphone silicon, had Intel been able to deliver 2H this yr, as originally planned.
But prolly the biggest single factor was them sharing resources, spreading the load so-to-speak, on developing the base software for x86 handsets.
But Nokia was being left to do all the heavy lifting w/ARM (it hadn't done a massive amt with meego proper TBH though), until such time as Intel could get their silicon out.

It's a misnomer that the tie-up was the major factor in slowing things down though.
There were things happening before/after the tie-up internally @nokia, which had a bigger impact.
Nokia hadn't even got to the point yet, where they were truly running with the project.
That was still some way off before the change in strategy was announced...