Yes, if one drive fails in a 0+1 array, replacing it returns the array to 0+1. In fact, it is possible for two drives to fail without data loss (but not any 2 drives).

READ THIS; VERY VERY IMPORTANT:
If you are using any kind of onboard or "software" RAID controller, DO NOT use RAID 0, 0+1, or 5 for anything that you would mind loosing. Software RAID is notoriously buggy, and often breaks arrays. On top of that, most software and onboard RAID adapters will then attempt to repair the broken array, and doing this will often wipe the disks. The only safe onboard RAID method is RAID1, as there is no need to rebuild when the controller screws up.

If you have a quality hardware RAID adapter (something with onboard RAM and a chip that gets hot in spite of having a heatsink), then RAID5 is probably your best bet...it will give you more space than RAID 1 or RAID 0+1, and it will have higher read speeds than either of those. The write speeds will be just a hair slower than RAID 0+1, but will be faster than RAID 1.