A few years ago it would have been a pipedream but with China aggressively deploying high-speed trains within its borders the possibility of extending them to connect Asia and Europe looks more and more realistic.
“Two lines to Europe are reportedly being considered under the proposals, one passing through India, Pakistan, and the Middle East, while a second would head to Germany via Russia. Exact routes are currently undecided however. A third line would extend south from China to connect Vietnam, Thailand, Burma and Malaysia.”
If not high-speed all the way, there is also the option of slower but competitively priced freight trains as one which completed the journey in 15 days in 2008. This paper looks at the economics compared to air and sea alternatives available today.