There was a totally new group of results flickering in and out at about 2am pacific time the morning of April 1st.
If those results are what they are aiming for with caffeine, then they have nailed things pretty well. The results were caffeine influenced, but very different than the spammier caffeine-ish results on the different IP addresses. This is to be expected as the IP address results are never what actually appears on Google. The extra dose of secret sauce between IP address and display on Google has always seemed to be what caffeine lacked, but this batch that appeared briefly did have it.
Of course, whatever... they may not even be able to find their car keys for six more months, let alone this more mature bunch of data, but that date was the most significant development so far "after the holidays".