Is this after you have exported to pdf/image, or within desktop?
it is within desktop.
It will be even more noticeable when published. This is to do with the rendering engine technology choice (HTML5 canvas).
Would it be possible to do a screenshot in different browsers, IE8, Firefox, and Chrome? This issue came up in the 8 beta forum, and is largely unresolved.
There is another related issue, that of table spacing/cell spacing/padding due to the difference in the specifications (of the way tables are drawn). This leads to inconsistent framing. (It can look like lots of iframes with scroll bars all over the dashboard). This is highly inconvenient as there is no "grid" with "safe zones" to allow pixel by pixel designing.
Quite simply, HTML5 canvas might be more efficient (faster and draws more data points) but less effective (blurry text).