No there is a 0% chance of bricking your phone because anything you did inside the Linux kernel in the first place will/can be totally erased by re-flashing your phone with a stock rom. There are lots of ways to irreversibly brick a phone but rooting it isn't one of them.
Let me try to change the terminology a bit, by gaining su access (su=super user) or "rooting" an Android phone all your really doing is changing your account type. Look at Windows for example I'm sure many of you are quite familiar with that.
You start as a typical user account and upgrade that account to admin that's all it really is, you may mess up somehow if you try to play around in a terminal bash prompt window but highly unlikely you would even try especially if you didn't know what you were doing. Even if you did you'd just re-flash and end up where you started.
Don't want to double post so I'll just add to this a bit here is a screenshot of my rooted (and somewhat modded) Samsung Moment:
As you can see no silver tab at the bottom and even though you can't see it since my screen capture app doesn't snap it the top taskbar isn't silver it's a blueish black gradient with customized icons. Also this isn't an HTC made device and this device techically doesn't have Android 2.1 yet, although it is running a DD10 leaked 2.1 Eclair ROM build.