  Precision cosmological data hint that a dark energy with equation of state $w
= P/\rho < -1$ and hence dubious stability is viable. Here we discuss for any
$w$ nucleation from $\Lambda > 0$ to $\Lambda = 0$ in a first-order phase
transition. The critical radius is argued to be at least of galactic size and
the corresponding nucleation rate is glacial, thus underwriting the dark
energy's stability and rendering remote any microscopic effect.
