I hate the physical sensation of flying so I always go by eurostar.
I've never seen eurostar less than 3/4 full. The French high-speed trains are amazing. I think Toulouse to Paris takes little over 2 hours.
But what I'm looking forward to is being able to travel from Kings Cross to Beijing via a Chinese bullet train :
www.telegraph.co.uk/news/worldnews/asia/...ed-rail-network.html