Initiative is almost always extremely valuable. Its value, roughly speaking, is the % of time it lets you "win" init over your enemies (say 5*# you gain) divided by the number of turns per encounter.
So, in 10 round encounters it's not that big a deal. In 2 round encounters, it's an extremely big deal.
So far, encounters are resolved in low numbers of rounds (much like my experience with 3e and 4e), making initiative one of the most important rolls of the combat deciding whether a PC gets to act once, twice, or three times in most combats.
P.S. So far one of the most hilarious points of playtesting occurred when I let the halfling monk who took Drive use it on a barrel of water down the street to put out a fire.