Sell for now. I don't think the team is getting worse under Mullen, but it does appear to be going through some growing pains. It happens with a lot of teams as new coaches come in.
It took Frank Beamer 6 years to get to his first bowl win at Virginia Tech. Since that time they've been a bowl every year.
1987 Virginia Tech 2–9
1988 Virginia Tech 3–8
1989 Virginia Tech 6–4–1
1990 Virginia Tech 6–5
1991 Virginia Tech 5–6
1992 Virginia Tech 2–8–1
1993 Virginia Tech 9–3 W Independence
Bear Bryant did not get to a bowl game in his 1st year at Alabama and lost in the Liberty bowl. It was his year 4 when he finally won his first bowl game at Bama. Granted, it was the Sugar Bowl, but I think you see where I'm going.
1958 Alabama 5–4–1 3–4–1
1959 Alabama 7–2–2 4–1–2 L Liberty
1960 Alabama 8–1–2 5–1–1 T Bluebonnet
1961 Alabama 11–0 7–0 W Sugar
As successful as Bama was under Bryant many people forget he had a couple of "bad" seasons where he was perceived as getting worse.
1969 Alabama 6–5 L Liberty
1970 Alabama 6–5–1 T Bluebonnet
A school that I look at as a parallel to our program is South Carolina. Even Steve Spurrier went "backwards" before he was able to build them to the program they are now. Also notice that he has only won 2 out of 6 bowl games and didn't even get to a bowl game in year 3 at South Carolina (although they were bowl eligible). In any case, he didn't even have 8 regular season wins in his first 5 years there. Mullen has already had two 8-win regular seasons. Furthermore, I think Spurrier was left in better shape after Holtz left than Mullen was when Croom left.
2005 South Carolina 7–5 5–3 L Independence
2006 South Carolina 8–5 3–5 W Liberty
2007 South Carolina 6–6 3–5
2008 South Carolina 7–6 4–4 L Outback
2009 South Carolina 7–6 3–5 L PapaJohns.com
2010 South Carolina 9–5 5–3 L Chick-Fil-A 22 22
2011 South Carolina 11–2 6–2 W Capital One 8 9
2012 South Carolina 10–2 6–2 ?
These are just 3 examples. You could go on-and-on. Of course, you can also find examples to the contrary; but, taken in the context of where the program was when Mullen took over and right now I still think he is doing a good job and the program is heading in the right direction.
My overall point is that there are going to be some setbacks. How the coaches, team, and administration respond to those setbacks is key. Will they shake off this loss, make adjustments, and be prepared on bowl game day? If adjustments need to be made at the staff level will they be made, or will we see a Croom-esque stubbornness to making necessary staff changes? And finally, will the Athletic Department let Mullen go if need be? We have who we have. What we do with what we have is what I'm waiting to see. Until them I'm selling.