Hum,
yea ive thought about the stability of the red-shift as well...
(For the uninitiated the redshift denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a remote galaxy provides an estimate of its distance. The distances indicated for this new galaxy are based on an age of the Universe of 13.7 billion years. At a redshift of 10, the Lyman-alpha line of atomic hydrogen (rest wavelength 0.1216 μm) is observed at 1.337 μm, i.e. in the near-infrared spectral region.)
This is to assume that space has been expanding at a constant rate, in a nice linear fashion.
If it were to be found that space is expanding faster today than in the past then the distances involved would correspondingly contract...(If, acceleration had a influence on speed of light)
(And there are indication that this is the case)
EDIT:
By measuring 16 new Type Ia's in Hubble Space Telescope images, (some with redshifts as great as 1.6). astronomers have determined that the universe clearly started accelerating about 4 to 6 billion years ago (at roughly redshift 0.5)...
This was when the density of matter thinned out enough, due to cosmic expansion, for the dark-energy repulsion to start overpowering matter's self-gravity...
The dark energy's "equation of state," (a quantity knows as w ), may change with time. (eg. Is dark energy some fundamental property of space, one that exerts a constant force per cubic centimeter regardless of how space expands? Er, like Albert Einstein's idea, of a "cosmological constant," with w fixed at a value of –1; Or is dark energy something in space, such as exotic particles, `quintessence`, that thin out as the universe expands, causing a changing force for acceleration?)
