The problem isn't the offense per se. It isn't the players on defense or the defensive coordinator either. The problem is there isn't any emphasis on defense coming from Leach at the top. Every decision he makes is based solely on how it will affect the offense. How many times have you seen Tech gamble on 4th down only to leave their defense in a bad position? Football is an unforgiving game, and those kinds of decisions will add up over the course of a season - usually to the tune of about four losses.
Another problem I see is that defenses are starting to have more success stopping Tech's offense. Despite the fact that offensive talent has increased dramatically (there has never been a better combo in Lubbock than QB Graham Harrell and WR Michael Crabtree), the scoring has seemed to level off. Missouri was able to hold Tech to 10 points last season, and just two years ago both TCU and Colorado held them out of the end zone completely.
All that being said Tech will still win 9 games this season, fill up the stat books, boast the best pass/catch combo in the nation, and continue to impress people who like their football to resemble video games or - even worse - Arena Football.
KEEP AN EYE ON
Defensive improvement everywhere but on the scoreboard. When your main goal as a team is to score as quickly as possible and never punt, you're bound to lose the time of possession and field position battles, which can make for some tired defenses in crunch time (see Brandon Pettigrew running through the D for the winning TD last year - at about the 4:20 mark of the video).
Wide receiver Detron Lewis. The sophomore had a big Gator bowl performance (100 yards, 2 tds) and he takes over for the departed Danny Amendola. That means you can pencil Lewis in for 100+ receptions and 1,000 yards.