I've sent my email feedback on this, and I'll add a thought or two here. My initial thoughts are that local alerts in 1.7 are a disappointment and a regression in functionality. Not only do they not alert me when the phone is off (not a trusted system for reminders), but now I have duplicate alerts to click through as I've decided to keep calendar notifications on for the audible alarm.
I had hoped that with local notifications, we would see various options for alerts for start times, due times, audible and/or vibrate options, silent times for no audible alarms, etc. Hopefully the thinking behind the current implementation can be revisited in the future. If not, I wonder if an API could link OmniFocus to a third-part app such as Boxcar?