+1  A: 

To be honest, I know nothing about PowerBoots. However:

I think you're on the right track as far as preprocessing the text goes. You're going to need to parse the text from the tweet and figure out what's an @ reference, what's a hyperlink, etc.

With this knowledge, you can then begin to populate your TextBlock, as I think you've tried to do in the code you've presented. However, you're right in thinking that a Label is not the right choice. In fact, the Element that you want is called a Run. A Run is little more than a run of text, hence the term. Ultimately, for your simple example, the code would look like:

boots { border -borderthickness 10 -cornerradius 10 -borderbrush orange `
{ textblock { `
    run 'Rails on IIS7' -backgr green; hyperlink 'http://is.gd/vWPn' -backg 'red' } `
} } -width 400

assuming I got the syntax for PowerBoots right.

dustyburwell
If you work with PowerShell, check PowerBoots if you need to use WPF from PowerShell. http://huddledmasses.org/powerboots-tutorial-walkthrough/I haven't seen this "Run", because it's not listed in controls list. http://msdn.microsoft.com/en-us/library/system.windows.controls.aspx However, it works now much better. Thx
stej