The B-1 suprised us all and started working, it doesn't need replacing.

Like the B-2s, however, the B-1 cannot operate within acceptable cost and
deployment parameters, a fact apparent to mission planners as early as the
mid-1990s. Consult the Gulf War Air Power Survey (available online through Air
University's website or at fas.org), or at least the concluding report,
published seperately and widely available. The 52s will continue to serve the
baseline deployment function in virtually every conceivable, plausible current
mission scenario. Or at least every one for which we're presently willing to
budget.

Any defense wag will concede the dilemma of current development of both fighter
and bomber aircraft, namely that the systems-integrative character of
contemporary air power projection renders the sophistication of these platforms
massively redundant. What matters much much than the cutting edge character of
the platform is how seamlessly it fits together with the many, many other
components of the standing doctrine. When deploying a PGM, especially the
garden variety versions, experience - to say nothing of theoretical studies -
demonstrates that comparatively inexpensive platforms like the F-16 complete the
tasks much more cheaply and effectively than the 117s or 22s.