I have the exact same situation but am finding it difficult to get any facts or even opinions about the merger.

What we (and others in our position) need to figure out is whether Yahoo will be completely taking on Bing's organic results or really "merging" their own organic results with Bing's.

I don't know the definite answer to that. Does anyone?

Based on the complete lack of response here, I think we better just cross our fingers and hope that current Yahoo rankings play at least a part of the "new" rankings when the "new" rankings do indeed appear.

It looks like a complete question mark right now. No one really seems to know much at all.

I got an email from Yahoo! search marketing today regarding organic search. It sounds like Yahoo's organic results will display Bing's results for 30% of the search queries starting in Aug/Sept.

No way to know for sure.

I don't think anyone will know for sure, however, Yahoo have indicated that it won't just be a copy of Bing's data. They'll be tweaking the serps, or inserting other data.

The test is running and i'm sure the serps will change, even after the test.

I'd suggest taking a good look at Bing and check the following:

Is Bing or has Bing spidered your site?

How often does it spider?

Can you find your site in Bing's SERPs?

Note its position in a spreadsheet.

Can you see your competitors' listings in Bing's SERPs and how are they positioned?

Start to analyze your competitors' sites (Page title, meta data, internal links, external links, inbound links, etc.) and look for patterns.

Start a changelog and change only one thing at a time.

Monitor the results before changing anything else.

Check SERPs and be patient.

Expect to see changes over time, like 3-6 months, so patience is important.

Actually, Yahoo won't be tweaking the organic results. They should be in the same order as Bing. What they do around those organic results can differ from Bing.

As of right now, from the US, Yahoo is showing Bing results for multiple keywords across multiple domains for my clients. Looks like the changeover is very close.

For my relatively new sites I've found all of the big three to be totally erratic, up on one while almost unfindable on another. Just basic seo no tweaking, some directory submits. First on page one (ok sometimes that's a given for new submits) then falls to page 7-10, then grinds its way back up to vanish again, only can found within a quotation marks title search, then back to the top ten for a day or two, then only found by a full domain search, then only the privacy page is being found for the title search in quotes in google while in 2nd position on bing third page on yahoo. Totally weird.