dmosbon: no stats counter is perfectly accurate, mainly because of the difficulty in distinguishing between a real human who is actually reading your blog, and the myriad of weird and unexplained scripts, bots, spiders and other critters that request web pages.
One of the likely explanations for a discrepancy between WP stats and another stats counter is in their respective definitions of "today" -- WordPress.com always considers today to mean "since midnight GMT", other stats counters may use different time zones.
wpvstp, sorry to burst your bubble but WordPress blog stats doesn't use Google Analytics. WordPress.com staff do use Analytics to collect certain aggregate site-wide stats, but that's entirely separate from the stats we record and display for individual blogs. (And yes, we do use WP stats for monitoring traffic on the WordPress.com blog, faq.wordpress.com and so on).