While I do think there was almost certainly some loose copying that happened (from the little I know of such, not enough to cause trade-dress problems, however), your link is a bad example. That could just as well be The Standard E-Commerce Theme. About 90% of e-commerce shops have the exact same elements on every page.
It's not the layout or the elements positioning, it's the style. You can clearly see that they've seen style choices fab have made and copied them, for example here is 4 things: http://i.imgur.com/8ONGa.png
I don't think it's plausible for ToM to have "coincidentally" made identical style choices to Fab, they're just too alike to not be intentional copying.
Fab.com is not some amazing technology, it's not going to change the world with 1s and 0s, Fab is a brand and the way their website is presented is important to their brand. The style of something is the sum of all its parts, it's the way something is designed and presented. Sure, on the face of it having a clock next to the time to go is meaningless and sure having a tag next to the price is meaningless, but when you have a website made up of lots of things like that it becomes their "style".
To me it is absolutely certain that ToM made a concious effort to copy the style of Fab, through the composition and presentation of individual elements and the layout of the site.
Branding is very important and can very easily confuse consumers, maybe Fab are being overzealous and should have just asked ToM to stop copying their branding, but to claim that because lots of websites have clock graphics next to their timers that this isn't a copy is silly.
For trade dress infringement the design elements can't serve a utilitarian purpose. So clocks and price tags used as icons to convey meaning don't count.
I'm not arguing the legitimacy of the lawsuit, I'm arguing that Garry and ToM are being disingenuous claiming that fab.com are just trying to shut down their competition, when it's quite clear to me (and others here) that the style of ToM is copied from Fab.com.
Whether or not they will win in court is irrelevant, what matters is that what Fab.com is claiming (ToM copied them) is (in my opinion) an accurate claim.
There are a lot of different ways to do things. Any one of these alone would be meaningless. All of them together certainly suggests to me a probability that the author of the second page was substantially inspired by the first.
It's called a trend. If you look hard enough I guarantee you'll find a website that is older than fab.com that looks very similar.
To win a suit for trade dress infringement it's not enough to prove the designs share similarity. The plaintiff's design must be truly distinctive and closely associated with the site.
I don't see anything distinctive about Fab.com's site, it looks exactly like dozens of other e-commerce sites. Furthermore no one is going to look at a product page with a picture on the left some, a white background and grey helvectica and think--Fab.com.
