I downloaded this about 3 months ago to test it on my 2+. I noticed that I had only 16 days left on the 90-100 day trial period, so I researched to find if there was a way to extend the trial period. I'd like to share my findings:
Info about the trial and the download:
http://technet.microsoft.com/en-us/evalcenter/cc442495.aspxDownload available until 12/31/2010.
Tool to convert the ISO file to a DVD:
http://store.microsoft.com/Help/ISO-ToolYou start the activation during the first 10 days and it counts down the days starting with 90. If you need more time, before the 90 days are up, you can reset the license to start all over again (at 100 days max). You do this by typing "slmgr /rearm" at a command prompt and reboot. If you are curious as to how many rearms are left you can type "slmgr /dlv". After doing this once (rearm followed by activation), I found that my activation expiration is in 90 days and that my remaining rearm count is 4 (see attached). Therefore we can conclude that the 90-day trial is actually good for up to 600 days (including the 5 rearms).