This season is most likely a lost cause in terms of achievements. If we can stay up with unsworth in charge then I say give it to him until the end of the season and get a new manager then. We'll have time to assess all options then rather than be tied into an allardyce type character for the long term when that really isn't what is needed.
The only problem would be the Jan transfer window. I'd say get in a new striker, see what defensive bargains there are out there and make the signings a collective decision between Walsh, unsworth and the board. Big money signings without a permanent manager without a long term plan is never a good idea. Also it gives the current players time to gel and by the end of the season we should be seeing the best out of a bunch of players who are quite frankly ten times as good as they're currently showing.