With BoM giving 5% mastery now and a little reforging, that puts me at roughly 30% mastery and 18% crit. A 30% shield is pretty amazing considering my holy lights alone are now critting for about 50k. Skada is throwing some interesting numbers at me as well. Averaging 23k HPS through 5 man HoTs with illuminated healing generally doing 25-30% of the healing. Hopefully someone smarter than myself will put up some math on this soon... regardless, it appears mastery is extremely attractive if only until the nerf in 2 weeks =]
Mastery did not really got any stronger with the patch. Just because we got 5% Mastery for Free, does not really increase its value.
That said, although the stat itself didn't change, our need for it did. Haste is still our 'best HPS' stat. However we no longer need to consider just HPS. Before the patch I am sure most Holy Paladins would agree that mana wasn't ever close to being an issue. We could spam all we wanted and liked more haste for even more spam. Now that mana is 'tighter' we can no longer do that.
Mastery although not changed, whilst slightly behind Mastery in terms of HPS gain, has the added benefit of not consuming mana in order for the gain. This significantly increases its value, now that mana is supposed to matter again.