Chevron has what's close to a jailbreak. I personally just paid the developer unlock fee of $99 to Microsoft. You can then "side load" XAP files (the actual programs themselves) through a desktop app from MS as if you were a developer working in your app like they do in iOS. Microsoft actually embraces the indie developer and works with the Chevron Labs. I think the only app I have on the Titan is a screen capturer. I needed it to make better wallpapers and stuff.
I left the Apple world to avoid the cat/mouse game of jailbreaking so I figured why be official and enjoy the OS as it is. It has everything I needed when I was JBing an iPhone anyway..
for me at least.
Sent from my kick-*** Titan using Board Express