AppleInsider reports that the MacBook refresh came as a part of Apple's 2009 Back-to-School promotion which offers a free iPod touch to those that purchase a new Mac for college.
The new 2.13GHz MacBook gets an incremental jump from a 2.0GHz processor and its 120GB hard drive gets replaced by a 160GB HDD. Base RAM is still 2GB but the system bus gets a boost from 667MHZ to 800MHz.
The price remains at $999 ($949 educational). AppleInsider notes that this is the second revision of the low-end MacBook this year, the other arrived on January 21st by way of an updated NVIDIA's 9400M graphics chipset.
Not an earth-shattering upgrade, to be sure, but an nice incremental jump nonetheless for a Mac buyer on a budget.