Oooh goody a direct question for me.
Although anyone else can still chip in and help too!
I haven't read your log in awhile, so I'm just going by your avi message. At 10 weeks or so you would be best served by making sure to train heavy enough to maintain muscle mass, frequent enough so that it isn't too tempting to wipe yourself out nor leave muscle groups for a week at a time (important in contest prep, a lot can change in a week).
So twice a week is a good move, although 10 reps on all exercises isn't ideal. Try to use several exercises ranges. So day1 might have 2 major chest exercises done for 5 and 10 reps, while day 4 might use 4 and 8. Basically though, unless you are trying to deplete muscle glycogen stores for refeeding, try to keep the loadings at or above 75-80% of 1RM (for me this is around 6-7 reps for you it may be as many as 9-10).
Pre-contest is also when "isolation" (really should be called emphasis) exercises become important. Not only do you need them, I'd say they are key to bringing up (well maintaining really) weak points. Get a critical look at your physique and decide what areas need the most attention, what your strengths are (to help with posing as well). This will help decide what needs to be done first on each day, what you will use isolation exercises for to pre-exhaust, etc.
Isolation exercises it is usually best to use slightly higher rep ranges due to the smaller involvement of secondary muscles. But pick them carefully to compliment the major exercises.
Diet is going to play the biggest impact on the actual volume of work you do on any given day. So I think pairing the two is a good idea (though diet is not my forte). Don't be afraid to remove sets from a workout due to fatigue, just make sure the level of stimulation the muscle recieves is adequate.
Hope this helps. Anyone else have anything, especially on integrating diet?