I should say brilliant..or as they say in Urdu..Afreen!!

Maybe I'm wrong but it seems the only difference from what already happens, and what still happens at google.com is the alignment within the search box. There's no impact on the flow of text, which is already perfect, even for bidi queries. (And in my little test there didn't actually seem to be any dynamic adjustment of alignment – things still seemed pinned to the right on RTL pages and pinned to the left on LTR pages, regardless of word order.) What I've always found more impressive is that google suggest works so smoothly, even in complicated bidirectional phrases.

Alex, it's the dynamic alignment in the search input box for your query that is new... the result pages remain statically left or right-aligned...

Philipp, you have to brush up your Hebrew! -)

not working for me
running any hebrew or english search at www.google.co.il result in all right!

Ofir: Read Philipp's comment again. It's about the direction in the search input box NOT the results page.

You can always read arabic text (no matter in which direction it is), but it's inconvenient to write in the wrong direction. (I call it direction because for me it's something else than alignment. In You can write in right-to-left direction while aligning text to the left). As the last paragraph states, it only gets tricky with special characters (spaces, punctuation). Also, the cursor scrolls in a wrong (no consistent) way when using the right-arrow/left-arrow keyboard keys.

I've compiled a video to show the differences (didn't compress it well though): http://ramibotros.googlepages.com/capture.htm