I think Dodge & Cox is an excellent firm, and usually keeps the turnover very low. So, I would expect any new fund they introduce will also have a low turnover, thus being tax efficient. If you want something even more tax efficient, use stock index funds like the VTSMX + VFWIX combo or the new single global stock index fund -- stay tuned for this one. I think that a new fund like DODWX will likely slowly build up its positions (probably will spend some time just building up cash), so will probably not have a lot of capital gains right off the bat. I would check out their web site for more info.

If DODFX has a lot of unrealized taxable capital gains, I would keep it, and just add new money to DODWX in the future (an excellent fund for taxable, IMO). You could also offset things by using DODGX. If not, I probably would bite the bullet, sell DODFX, pay the taxes (if small), and put it all in DODWX. Of course, a lot of the decisionmaking process also depends on your asset allocation, and how far out of whack any move would cause.

Dan