Question:
I am usually way too impatient to wait for an auction, so my favorite eBay vice has been doing a search with "buy it now" items shown. Apparently eBay has an Express store at http://www.express.ebay.com/ and I was only alerted to its presence by a seller letting me know that I could go there after I said that it was a pain in the neck to have to pay for all the items I bought from her separately since she had them listed as "buy it now, instant payment required" instead of as a regular auction with the buy-it-now feature.
HOW LONG has this been up? I can't tell you how obnoxious it is to buy multiple items (lately for me it's been MAC Lipglass) and have to pay for them separately. Now they've upped the eBay addictive factor for me by at least tenfold.
Ahhhhh....Lutens decants, here I come.

Answer:
Not that long, I don't think. I started noticing links to it in the last couple of months sometime. I didn't realise what was keen about it however - but I can see that for buy it now / instant payment required auctions, that could be useful - and possibly allow for combined shipping costs to boot.
In the past I would just email the seller to say I wanted multiple items and go from there, sometimes s/he would set up an auction for me.