Bar charts was a great idea, and much easier to visually analyze and compare, but i do believe its quite bugged atm. What really disturbed me: Mouseover tooltips on some days show only the date of the bar and number of visitors on the appropriate date without showing what posts have been published on the same date. Or at least some of the days do show all the info as before. I do hope that wasnt done on purpose and can be fixed.
Also if i may, i thought about two usability issues referring to site stats (btw why change "blog stats" to "site stats"? Something else coming up?)):
a) there's a down arrow in the right top corner of "windows"-modules. It works quite the same as clicking anywhere else at the same height of the module. I personally enjoyed seeing yesterday and today data one above the other. Now to compare i have to click back and forth and try to remember these stats. Why not make click (or even double) on the top half expand the module downwards so that data could be matched (like it was before being an elongated to the downside module)? And the down looking arrow leave as it is performing the "common logic" function of minimizing or expanding the module. I dont want to perform site stats research several times a day on a daily basis. But comparing two consecutive dates on the relevant aspects is quite enough for my purposes.
b) And about the bar chart. About the mouseover tooltips. You can roll inside the tooltips when they appear and see the titles of the posts on that date, but you can only copy them. Wouldnt it be more practical that instead of text you see a link to the appropriate post?
Hope this is praisal and suggestion section.