http://wow.joystiq.com/2011/09/29/patch-4-3-raid-finder-feature-preview/

"Q. Will I be locked to a raid I join through the Raid Finder?
A. Since the Raid Finder only offers access exclusively to a specially tuned version of the Dragon Soul raid instance, instance locks will not be enforced for that version. Instance locks will still be enforced for the normal and heroic versions of the raid."

They are separate, and you won't be locked out of your regular raid.

Yes, but that does not answer the question of eligibility for loot. Once you do a boss on the Raid Finder, you are no longer eligible for their loot that week. I want to make sure that does not carry over to non-Raid Finder raids.

This is what I find vague:
"Also, while Dungeon Finder raids aren't locked, you are only eligible for loot from a boss once per week. This means that if you were present for the defeat of a boss, whether you receive loot or not, then you will automatically pass on loot that drops during later attempts on that boss during the same week."

"Since instance locks aren’t in play, Raid Finder raids could provide a way for dedicated raiders to... fill gaps in their itemization" from the same article. The implication is that Normal-mode raiders will be able to get loot from LFR *after* their scheduled raid.

I get the impression that the "loot-lock" will only apply to drops off bosses downed in raids formed through the Raid Finder. We will be able to kill the same boss multiple times per week, in different RF raids, but we won't be eligible for loot after the first kill.

Guild/alt/pug raids formed without the RF will likely stay the way they are right now and the two won't really interact.

The vague part you are referring to is intended to allow people who drop from a LFR group after 2 bosses to join a group later in the week. They can still participate in the kill of those two bosses, but can't get loot from them. I believe the blue post was quite clear that the LFR group is ENTIRELY separate from Reg and Heroic Raids. Since it is entirely separate then you will still be able to receive loot from reg or heroic kills even after killing a boss or clearing the entire raid in a LFR group.

The decision to not lock you from a boss after it is killed in LFR will also, as described in the blue post, allow raids having difficulty with certain mechanics the opportunity to practice that mechanic multiple times in a week.

Thanks for the responses. Killik, upon re-reading the section you quoted from, that does seem to be a pretty clear indication that you can do both.