My nephew had his returned within a week after he re-applied last month but I don't know what the norm is,when I last did mine and Trish's about four years ago it took about three weeks. I think it depends a bit on if it's a new application or a renewal.
it'll probablly depend on how many applications they're dealing with. As people have suddenly realised that they may need a new passport to go to the USA, there may be a sudden rush.