You'd posted a question on that thread about what to do with the floor. We also opened up the wall between our kitchen and DR (FWIW we have decided to turn the DR into the LR, and the LR into the DR--better use of the spaces that way for us).

We have the original white oak floors throughout the upper level of our bi-level home (built in '67). The kitchen however, did not have HW. When we ripped out the old kitchen, we had white oak installed to match the old floor. Our floor guys weaved a new white oak floor into the existing floor in the DR. I believe they said there would be about 10% waste (of the old floor). They used whatever grade of oak that would "blend" or match the existing floor. All floors were sanded down to bare wood, and one coat of finish applied, with the final two coats to follow at the end of the reno (after the cabs and appliances were installed).

Unless you are looking for it, you really don't notice a difference and that's just barely (and I am very picky, and very detail-oriented!). If you stood in the DR, and looked across the entire DR/kitchen floor space (before the cabs were installed, especially the island in the middle of the kitchen), you could see that the newer boards were ever-so-slightly fresher and brighter-looking (a hint less yellow) than the older boards. Again, that's just because I knew, and was looking for it. I highly doubt anyone else would ever see it, even if I pointed it out.

With the kitchen completed, with an island and counter stools sitting in the middle of the room with just a few feet wide HW floor space on either side, the minute difference is even less apparent (if that's even possible!).

I have to add that our floor guy told us that the new floor will eventually yellow a bit, as the old floor did(even with waterbased poly it happens), so at some point even I might not be able to tell any difference at all!