To Tony Fernandes, X doesn’t stand for Xpress but Xtra long.

(SOURCE: BBC, 5 January 2007)
"We are proud in being able to continue to lead and revolutionize aviation industry in Asia, just as we did with AirAsia," […]
"Ultimately the launch of AirAsia X will bring independence to the long haul low cost traveler by providing a choice of service for their long-haul travel requirement."
Starting from July, AirAsia X, a new long haul budget service by Fly Asian Xpress (FAX), will start operations in July by flying to Manchester, Huangzhou and Tianjin with the lowest ticket price at RM9.99, targetting to be on sales from next month.
The Transport Ministry has granted AirAsia X landing rights at 36 international destinations in Asia, Europe and Australia. Among them are Sharjah in the United Arab Emirates, Melbourne and Osaka.
Despite rumours that AirAsia X would tie-up with the United Kingdom-based Virgin Group and EasyJet to launch this, Fernandes named no partners. However, he admitted there is on-going discussion with easyJet and Virgin Atlantic and would tie up with other low-cost carriers "in order to increase connectivity and route network".
Meanwhile, NST reported that MAS in a statement, national carrier Malaysiar Airlines (MAS) said it is confident that there is room for both a full service airline and a long-haul low-cost carrier in Malaysia.