1.you will loose root if you accept the ota. once you are rooted go to settings/system update/ htc software update/ and uncheck scheduled check. that way if there is an ota you will not be notified.
2.gingerbread is already out. there are a few non-htc sense roms out there that are using. but because it is a non-sense rom it does not have 4g or hdmi working (there is a beta of cyanogen mod 7 that has 4g but no hdmi). once the htc sense for gingerbread is out, the rom developers will eventually be able to port that to their roms. we just have to wait for that to happen.

have you read this:
http://androidforums.com/evo-4g-all-things-root/194918-rooting-dummies.html

it is the best guide out there.
any questions please feel free to ask.

 

+1. I used this guide and it worked without a hitch.

 

Not only should you not accept an OTA update, but it likely will not work. OTA updates rely on the stock recovery, which you will have replaced in the root process. In order to accept an OTA update, you would have to restore the stock recovery, then accept the update. The problem is that you'll have S-OFF (full root), but with an hboot that cannot be rooted (until an exploit is found). That means that if *anything* goes wrong, you'll be without root for a while. The better way to update is to update to a rooted ROM based on the latest OTA. It doesn't have to be a custom ROM. It just has to be a rooted one based on stock. Then you need to update radios. There are instructions for this in the previously linked to Rooting for Dummies guide.

 

Don't let it scare you . It seems like a lot to take in, but once you've done it, you'll be more comfortable. That being said, if you want to take more time to decide, and get more comfortable with the phone, that's fine. If you still decide it's not worth it, that's your decision. If you don't want the responsibility, then certainly don't go for it. That being said, another option you have is to simply unroot when there is an OTA, accept the OTA, then wait until you can root again. You almost invariably will lose root for some time (and *potentially* forever), and any nandroid backups you've made will be unusable (due to your hboot version changing). That's why we never recommend doing that. It's easier, but there are drawbacks. Anything you do to your phone while rooting can be completely undone, and taken back to stock. I'm certainly not tell you what you should do; if you don't want to root, that's certainly fine. I just want to make sure you understand that it's not as complicated as it seems . It just takes a lot of reading, and asking questions when you're not sure of something.

 

I say root if you really want to. Just make sure you understand ALL the basics, especially Nandroid.

Updated stock roms do get released out into the wild and can be flashed if you absolutely want updated stock UIs.

If you do Root (like previously said) don't use OTA updates.

HTC Supersonic/ROMs - XDA-Developers
^^The top of the page has all the Stock ROMs and the updated versions. This page also has all the different Roms currently available for the Evo.

 

If you do decide to root.....you will likely look back at it like most and wonder what you were so nervous about. It is a piece of cake. Follow the directions and if you have any questions, ask.

 

Not only will you be in full control over your Evo, but you'll have all the updates a few days prior to them being released publicly! Not to mention not having to pay $30/mo. for the sprint hotspot, to name one of the many perks. Look, it's none of our business whether or not you want to root, and it's not our job to persuade you to. We're just here to give you the correct information so you can make an educated decision. Good luck either way.