I think dormant pruning before growth begins is an adequate time to prune. Anytime between now and the beginning of new growth. Don't prune the branches up high, remove the oldest and/or most congested stalks at or near the bottom of the plant. You want to encourage more shoots from the base of the plant, and let the berries grow at the tips.

Dadgardens:

Wow, how did you get northern highbush blueberries ten feet tall? I have some plants that are 25 years old in pretty much ideal soil conditions, and they are still not much over 5 feet.

Agree with TCStoehr about blueberry renewal. Blueberries are not really "pruned" as such; older, thicker, woody canes are removed completely at the base to encourage the growth of vigorous new canes. Old canes tend to decline both in berry size and productivity. In my experience, the life of a cane is about three years before it should be taken out. The number of new canes that will grow in is usually self-limiting, but they should not be too crowded. 6-8 canes is usually enough on a mature bush.

At some point in the life of a blueberry bush, say after 25 years or so, an extensive woody base will develop above the roots and berry size and productivity will begin to noticeably decline. Flavor of the berries can still be very good, but there are a lot fewer of them. Very old plants cannot be "restored" in the usual sense of that word, and it is better to take them out and replace them with vigorous young plants.

I just removed and replaced two old blueberry bushes this week myself. As you describe your blueberry bushes, it sounds as if they may be at that stage too. Taking out the old bushes is quite a job.

Don Yellman, Great Falls, VA

In my area, many commercial growers are now pruning blueberries in early fall, before leaf drop. The thinking is that it's much easier to see damage or disease while the leaves are still on the plant. They spray fungicide within a couple of hours of pruning, copperoxychloride if I remember correctly.
Fall '07 was the second year I've seen this and the growers seem happy with the results. Their feeling is that the problems asssociated with early pruning cause less crop loss than if left till spring when problems are much harder to spot.
Only time will tell if this strategy will pay off.

I want to thank all of the posters who responded!I can log in again!

Dormant pruning sounds good to me, I'll do what I thought was right.

Jellyman, I had a herd of 24+ deer and slightly less than optimal sun in my patch (for a few years), I still get a fair yield (and some quarter sized fruits (from one bush in particular). The herd has been discouraged by fencing around the 3/4 of the yard and fencing around the bluberries). I'm hoping that my bushes don't need to be replaced, I'm not a commercial grower, and am willing to spend some time/labor on the plants (one in particular-big berries).

Saturday looks like a good pruning day (I know, I'll reduce the yield - but pruning is overdue). So, I'll give it a try!
DG

The problem with deer around blueberries is they sometimes go after the new shoots coming out of the ground. This is your source of good renovating wood and must be protected. It is not preferred food and they only browse it when very hungry but look out for it. Rabbits also go after this wood, leaving the tough older wood alone.

You have to be sure to remove enough wood to get light down
to these shoots so you must sacrifice an awful lot of your
crop to restore your plants.