By far, the best thing about the DVP is its beautiful curves. The road is also pretty well paved around these curves, thus at night when it's empty, it's a driver's haven. Or even early morning (6am). Anyway...
Tips from a daily commuter.
(This only covers afternoon traffic. I commute at around 11am-2pm up to Thornhill and down again at around midnight.)
Being the only route in East Toronto running north/south, rush hour for the DVP starts (going northbound) at around 2:30 PM and ends at around 7:30 PM. Catch it any time from about 10AM to 1:30PM and you shouldn't encounter any major slowdowns. If there's construction (as there often is, DVP was not designed to handle the load it carries), you might want to try taking Leslie up to York Mills then, if applicable, east to DVP where it should have picked up. (DVP turns into 4 lanes at York Mills) But definitely avoid Leslie when the Dimaond Lane goes into effect (3PM to 7PM in the afternoon.). Two lanes of stoplight-ridden 60kmh max street is much slower than three lanes of nonstop 30-40kmh traffic. Slow as it may seem.
If you're caught in it between these times, the leftmost lane is usually a good bet. AFAIK, the only possible thing to slow it down is at 401 where there are usually some jackasses trying to change two lanes over to make their exit. I've even seen one (admitedly old and forgiveable) just stop. Also, at Eglinton there are usually a whack of people getting off and there's a clear stretch of tarmack in the rightmost lane. Though, it's hard to take advantage of this without being an asshole as traffic has usually stopped at the onramp right after.
If you are stuck in the right lane, leave some damn space goddamnit. People moving bumper-to-bumper doesn't help traffic. The right lane(s) are for getting on and getting off. If you leave enough space for the people getting on to get on you don't need to slow down your car and every car behind you to let them in. Space can even be used to avoid braking when someone in front has to slow down to let someone merge. This means better milage and it could even be (gasp) faster.
For the speeders, cops usually hang out on onramps/offramps. The lawrence exit is popular for sounthbound. I think there's a slight downgrade there to give them some extra boost.
Update: 404/DVP North of 401 is now like 5 lanes. The OPP love to sit just south of Finch with their radar guns. Got me going a good speed the other day. Word to the wise.. | 
