Change your "Display Density" settings in the new Gmail...

While checking my gmail account this AM, I clicked on some thing that I thought was going to show me the "upcoming new look" of  gmail, but it actually switched me to it permanently... I like some things about it, but REALLY didnt like the (larger) height of the rows in the inbox... I could see about 1/2 the amount of messages per screen. BIG AND GOOFY.

Turns out you can change this thru the "Display Density" settings, which are available by clicking the "gear" in the upper right hand corner:  

 

And select a size from the drop down list:

By default the new layout is set to "comfortable which looks like this:

And changing it to compact makes it look alot more like the old layout:
(more inbox rows displayed!!)

Google's "Display Density" settings webpage