The good news is RIM implemented BIS 2.5 late last night/early this morning for North America. The upgrade brings access to HTML email, OTA (Over the Air) software updates, push email for Hotmail, MSN, Live and AOL email and the ability to now download a ton of attachment formats (doc, .ppt, .xls, .wpd, .txt, .html, .pdf, .zip). You won't be able to get HTML emails until OS 4.5 is installed on your BlackBerry.

The bad news is that most BlackBerry smartphones won't be running OS 4.5 till around September, unless RIM releases any new smartphones before then (which they will run 4.5).

[Source]