For me, it's theoretically auction 2. I say theoretically, because in practice I believe any auction would in fact be some variation on auction 4 but with considerable skew in the distributions.

: Will there be enough bidders to support Auction One, with its NOS
: and near mint pieces? Can the market absorb this auction of 100
: prime watches, with the NOS / mint premium for so many watches?
: Will this auction need to find new bidders, from the high-end
: Hollywood or London scene?

While I can maintain a near mint watch at near mint, I'm going to wear it so I can't maintain NOS as NOS, not in the true sense of the word, as I will wear it. So I can justify a premium for near mint, but not for NOS given that I am promptly going to negate its "NOSness". I would fear though that the seller and/or auction house would consider that the very top watches in the sale would give a halo effect to the price of the other watches and pitch the premium for condition higher than usual for all the watches in the sale, including those in mint but not NOS condition. This may be enough to push them into regions where I would consider that I could buy the watch in equivalent condition elsewhere and not attract a buyer's premium, making that the more attractive option for me. If the auction requires people who consider themselves part of a scene to be bidding on the watches, then that's a bad thing if it deters the serious marque collectors - it either creates a fashion bubble, which have a habit of collapsing, or affects the perception of the brand (Panerai? Those Sylvester Stallone watches?). Part of the draw of Heuers for me is the real (not invented) racing heritage and if the collecting community has a sudden influx of people who are unaware of, or worse uninterested in, this heritage, I think it would be a shame.

: In Auction One, will we see NOS premiums, for the best samples of
: the more common Heuers . . . will Viceroys and two-register
: manual Carreras attract these NOS premiums?

As above, I expect they would be priced as such because of the perceived halo effect of the very best watches in the sale. And please tell me where 3647s are particularly common, I will consider moving there!

: Can Auction One or Auction Two give the market a "lift",
: in the style of Omegamania, or was Omegamania a unique event? If
: the market can absorb the watches offered in Auction One or
: Auction Two, will it be flat or tired afterwards?

Omegamania wasn't the first single brand auction, nor will it be the last. However, Omega did not have the prominence of the brands who typically have these sort of auctions (Patek, JlC and that mass-manufacturer with a name ending in -x that I cannot currently place ;) ) and thus a high-profile single brand auction was able to have a greater effect on the market. Heuer is probably in that same sort of position. But let's be very clear about this - an auction of that sort and with that impact is only possible with heavy support from the manufacturer themselves. They can supply the one-offs, the (genuine) prototypes, the "OMG, it's one of THOSE!!!" watches that really get the collectors, and their wallets/purses/voluminous piggy-banks, interested in the auction. And those watches are the ones that really can provide the halo effect I talked about in auction 1. The lessons of Omegamania should also be learned - if the manufacturer is going to bid on some of the watches, it should be public and clear that you are bidding against them. That was always the drawback of the current single collector auction - I look at it, at least from a Carrera perspective, and don't see anything I haven't seen plenty of times before and know I can source reliably elsewhere. For a sale to have the impact of Omegamania, there have to be those watches that become essential because you never know when or if you are going to see them again. That's what would pique my interest, whereas the Patrizzi sale might be more for someone looking to start a Heuer collection from scratch or expand an established collection horizontally - if you wanted to add some Kentuckys, say.

: Are Auctions Two and Four, with the preponderance of really nice
: (but not NOS) watches, more attractive for the average, serious
: collector?

From my perspective, that's a clear yes. And at auction 4 I would be more likely to bid on the watches with higher premiums than I would at auction 1, simply as there would be more choice and I would be less inclined to just sit on my hands throughout.