Well when I did, the old interface was still intact. Previously Blogger stated that the old interface was going away in April, but apparently they extended it for a lot longer.
No one really knows when the old interface is really going away now, because "in the coming months" is not a very accurate answer. Users of the old interface is still going to have their fun, because obviously they still have their old interface.
Seriously though, when the old interface is gone, the new one will replace it. I suggest you start using it now, just to get used to it. No one likes the "OH MY G-D {product/object/you know what I mean}" feeling.
The new interface
The new Blogger interface actually isn't that bad as it seems. It aims to be a bit simpler to use. Of course you'll still have to get used to the new color sets.
Google has made it really easy to learn the new interface, because they have released some videos guiding you though it, and they also have their support pages. Their intro video is below.
