Jim Naughtie and Shaun Ley will anchor BBC Radio 4's Election Night Special from Washington, joined by Martha Kearney and Paddy O'Connell. http://www.bbc.co.uk/radio4/
RTE have nothing flagged on their website, nor do NewsTalk in Ireland. There are lots of podcasts avalable and information on the election itself, but the websites show nothing with regards who is where and when during the night. Mark Little is in the States for live TV hook-ups, but no mention of radio. If you find anything, let me know. I also heard that George Hook was due to host a special election broadcast, but nothing on the website http://www.newstalk.ie/
If you're near a Wi-Fi radio or want to listen online, then you could pick any of the hundreds of US News stations, but it can be hit or miss sometimes. Best bet from outside the US is http://www.npr.org/worldwide/
Find News stations in the US on http://www.thestreamcenter.com
Have fun...it's a media outlets dream night!