This isn't a review. The first Yosemite beta has only just emerged, and so it's clearly not ready for prime-time. However, although some of the new features demoed at WWDC 2014 are absent or broken, enough are baked to the point you can get a feel for how OS X is going to be later this year. Here are our first impressions on some of the highlights, after a day of exploring Yosemite.The OS X Yosemite interfaceOS X's interface is now a strange combination of stark minimalism, subtle colour effects and cartoonish icons. The stripped-back interface typically works well, and transparency effects in sidebars and behind toolbars are (surprisingly) subtle enough to provide a sense of place without being a distraction or interfering with legibility. Performance seems unaffected.The Helvetica variant used for the system font is generally legible, if lacking in character, but the spindly menu extras are less successful ? it's now hard to tell whether the network indicator is showing a connection.