Most every company I've worked for in the last 10 years has limited incoming and outgoing attachments to just 5MB (generous companies allowed 10MB). In my line of work, where high resolution images or the transfer of Photoshop documents are often required for articles or posts, this is a very limiting, er, limit. PowerPoint presentations, Photoshop documents, Quark documents, and other files can easily surpass 5MB, making them difficult to email if the receiver's email system has a low limit on the size of attachments allowed in.
Gmail has long allowed larger files to pass through its systems. To be honest, it is pretty rare that I ever have the need to send or receive a file larger than 10 or 15MB. Still, it's nice to know that the cushion is there, and files as large as 25MB will make it through.
The change is for everyone. So go ahead, feel free to find a huge file and attach it to an email and send it. Just for the sake of it. Feels good, doesn't it?