The new visual charts "show you the number of pages Googlebot's crawled from your site per day, the number of kilobytes of data Googlebot's downloaded per day, and the average time it took Googlebot to download pages."
Crawl rate control: "If you'd like Googlebot to slow down the crawl of your site, simply choose the Slower option. If we feel your server could handle the additional bandwidth, and we can crawl your site more, we'll let you know and offer the option for a faster crawl. If you request a changed crawl rate, this change will last for 90 days. If you liked the changed rate, you can simply return to webmaster tools and make the change again."
With enhanced image search you can opt into enhanced image search for the images on your site.