Worth reg fee. The extension only appreciate in value when there is no other words that can be registered and domains aint dropping anymore.
There are domain countdown threads you can follow to learn the 'value' of domains.
This is true for the following categories, LLL.COM, NET, ORG, NNNN.COM, NNN.NET, NNN.ORG.
NNNNN.COM, LLLL.COM, CCC.NET, CCC.ORG are all constantly dropping hence valueless.
Basically if you can freely register means they only worth reg fee.
If you don't plan to use the domain, drop the domain.
July 20 2011 will be the day .COs will on REDEMPTION PERIOD and then PENDING DELETE.
Domain portfolio holders need to skim and prune their portfolio when nearing that day and selling their domains at reg fee in order to hold and renew the better names they hold.
You will see MASSIVE sales in forums trying to cut loss.
They reg names as many as hundreds to thousands.
Every .CO renewal is approx $25 USD hence in order to renew all, they need to spent $25 * 100 = $2.5k USD minimum to hold on to their names.
It will be very financially exhausting.
I believe they can hold it for another year until July 20 2012 cause renewals after that they already spent $50 USD per .CO domains and if they are selling at reg fee they would not have much profitability hence July 20 2012 will be the year of MASSIVE drops.
This hype has been true for .info, .biz, .mobi, .tel, .asia and .me
.CO is just another hype. Everyone during the hype believe 'THERE WILL BE POTENTIAL' on this extension.
Each time new domainers come in and got their money burned, thinking old domainers will buy them.
Old domainers aint idiots. They had burned their money way before new domainers comes in.
It has been 10 FREAKING years since inception, LLL.biz still worth only reg fee, LLL.info slightly appreciated and all other newer extensions are worthless.