Gavin Andresen - 2010-07-14 01:44:36

No, actually, in the current source code it never gets lowered:
Code:
   // Retarget
    CBigNum bnNew;
    bnNew.SetCompact(pindexLast->nBits);
    bnNew *= nActualTimespan;
    bnNew /= nTargetTimespan;

    if (bnNew > bnProofOfWorkLimit)
        bnNew = bnProofOfWorkLimit;

    /// debug print
    printf("GetNextWorkRequired RETARGET\n");
There's no "else if (bnNew < ...something)"

UPDATE:  rodin is right, I'm wrong.  bnProofOfWorkLimit is a constant, and this code just make sure the proof of work never gets too easy.