Apple on Tuesday beefed up its plain vanilla MacBook with a tweaked CPU, more storage and longer battery life, among other things. However, it retained the device’s $999 price point. The upgrade comes one month after Cupertino refreshed its MacBook Pro line and just weeks before its World Wide Developers Conference, to be held in San Francisco. For the upgrade, Apple tweaked the MacBook’s Intel Core 2 Duo processor to deliver a clock speed of 2.4 GHz instead of 2.26 GHz as before. The new MacBook uses the Nvidia GeForce 320M instead of the GeForce 9400M.