The live feed is reporting that Ugly Betty is moving to Wednesday's at 10pm.
No date given other than "very soon".
To me that move says "We don't have a lot of faith in our mid-season replacements".
As for viewership levels, I don't have hourly averages, but on Wednesday November 11 @10pm 40.3% of adults 18-49 were watching television, and on Friday November 13 @ 9pm (UB's current slot), there were 31.8% of adults 18-49 watching television. So perhaps Betty's new hour has about 25% more adults 18-49 watching television.
Betty has averaged a microscopic 1.22 adults 18-49 rating this season on Friday (with no repeats). Even 25% better, that's just a 1.6 rating.
ABC didn't have something on the bench it figured could do a 1.6 rating?
Edit: Of course the headline should have read 10pm, my bad typing.