I am saying it is a good idea to install the latest IE8 simply because it is more secure than the older versions of the Internet Explorer. This is key, especially when some programs installed on your computer that utilize the internet, automatically open the internet explorer (ie.exe) and so, when this happens, you can rest easy knowing you are not opening the older, less-safe versions of the Internet Explorer.
I forgot to mention, this install of the IE8 browser is only available for Vista and Windows Server operating systems (right now). So if you are still running Windows XP you will have to hold on until the new Windows 7 O/S is released at which time you are going to want to get the upgrade since the new Windows 7 rocks!