[jonnyk]

I would prime the oil pump for at least 2 minutes before you start it up...this will get oil to all of the friction surfaces, and hopefully wash away anything that has settled on any surfaces. I doubt it will cause any serious harm to your engine leaving it like this.
After it's primed, run it (idle) until it warms up. At this point I would change the oil. The filter will catch anything else remaining and then you can start fresh.