There are a few things to keep in mind when transplanting blueberries.
- Blueberries like slightly acidic soil. So if it's growing well now, it sure does like the soil. When you transplant it to a pot and later to your new place, you should ensure that the pH levels are about the same so that the plant doesn't suffer a shock over and above that from regular transplanting.
- Blueberries don't have very deep roots. They have a crazy mess of shallow fibrous roots which can easily get damaged when the frost hits especially if it's not established.
That said, if you can ensure that the plant gets the same pH at your new place and if you dig enough around the plant to not really disturb the roots all that much, I think you have a shot at transplanting the plant. Also, since blueberry season is generally in July-August, the plant should be able to shake off the shocks (if you keep it to a minimum by being careful) and establish itself by then. Blueberries typically bear fruit year after year till it grows very old. Hence if properly done, transplanting shouldn't affect fruit production (maybe slightly decreased the first year).
Transplanting is a bigger problem with berries that produce fruit only on year old canes, as the shock can reset the plant's internal clock. When I transplanted my established year old blackberry plant a little over a year ago, it went into severe shock and lost all the canes it had produced and shriveled back to just a little stub and stayed that way till spring. This year should've been its second (fruit producing), but instead it started putting out new canes vigorously (now I understand why it's a weed in some places...). So although the clock was reset, the plant is still very healthy and will (hopefully) fruit next year.
All this said, I second bstpierre's pragmatic answer. Sometimes the trouble of waiting and going through the hassle twice (once to the pot and then to the ground) might just not be worth it. But if I were you, I would get a new one and transplant the old one, just to experiment with it and see if it works or not; that sure is a good way to learn and you'll have first hand experience at transplanting and also first hand knowledge of what happens to doubly transplanted blueberry bushes!