They work fine for my 8 Blueberry plants. I have a friend who uses Pine needles and sawdust. I amended with Azalea mix to help lower my pH and use Sulphur to help keep it low. It is also good to add Vinegar to water to help also.

There has been discussion of nitrogen loss due to wood chips-the soil micro-organisms that break down the wood, as it rots, take nitrogen from the soil, so its not available to the blueberry shrub. But wood chips, or whatever type of mulch you choose, helps to retain soil moisture and this is absolutely essential to keep the shrub alive and well. I am using shredded maple tree leaves, but I have no particular reason to think that this mulch is better than wood chips. To maintain soil fertility, I give each shrub one tablespoon of Miracle-Gro(acidic formula) in 4 gallons of tap water, in April, and again in May.

ericwi,
right now I have mulch of shreaded pine needles and shreaded oak leafs..they allow water to pass through and certainly retain moisture. Everytime I take a peak I find earthworms/redworms in moist soil...which is a good sign. Is it advisable to just leave it be? If the sole purpose of the chips is to retain moisture that is already happening with my pine and oak leaf mulch.

Your pine needle and oak leaf mulch should do everything you need. The one advantage of rotting wood chips is that they hold a lot of water which the soil will pull out of them as needed.

Oak leaves have more N and other nutrients than wood chips- to a lesser extent, so do pine needles.