A very welcome alternative for cyclists connecting from points east of Irvine to Laguna Beach is open. The spur extending Lake Forest Drive to Laguna Canyon Road is is complete enough that the County has dropped the barriers and allowed vehicular access, pretty much according to schedule.
Additionally, the missing segment of Bake Parkway past Irvine Center Drive (check it on the map referenced above) is also officially rideable.
Part way up you pass the Verizon Wireless Ampitheater complex, which is on its last legs (if a venue can be assigned anthropomorphic qualities). The road comes fairly close to the outer boundary of the upper lawn's cheap seats. Expect "No Parking or Stopping" signs to be up in short order.
First impression: riding from Lake Forest, it's a straight, gentle and consistent climb to where the road crests at the Laguna Altura community, and it's a short descent from there to Laguna Canyon Road.