Kaz Hirai explained the meaning behind the change to Times Online. The new logo represents a "reset" of sorts. Hirai explains that he wanted it to represent "going back to our roots."
There are practical applications to a revised logo, as well. "When you have PlayStation 3 spelt out, the aspect ratio was such that if you wanted it on a billboard it became tiny. It didn't work in terms of visibility," he admitted. We took a look back to this Call of Duty 4 TV ad to emphasize the difference: the Xbox 360 logo is more than twice as large as the now-outdated PLAYSTATION 3 logo. If you watched this ad on a SDTV, you probably wouldn't even notice the PS3 logo at all! While we're not entirely sure the new logo will have an effect on sales, we (and other games bloggers) are glad to finally give our CAPS LOCK keys a break. Thanks, Sony.