Despite reports to the contrary, Dell won't be dropping its desktop XPS line to promote its Alienware gaming PC subsidiary instead - though the company admittedly plans to expand their focus on the latter to propel it as "the premier gaming brand in the future."
A spokeswoman for the company emphasized that though the XPS line initially focused on gaming, it has grown to become a premium, cutting-edge brand beyond gaming - and pointed at their XPS One all-in-one desktop and their XPS M1330 ultraportable as clear examples of that. Likewise, Alienware was formed to create customized gaming PCs, but has extended itself into more mainstream markets.
What the company really intends to do, then, is continue investing in gaming systems through both their Alienware and XPS brands in a way that they complement instead of compete with one another. Alienware will focus on customized systems for gamers that deem price is a secondary concern, whereas XPS will be used to offer rigs for gamers who want high performance at a lower price. That said, Dell does plan to release a $1,700 AMD-based Alienware gaming system, so there's certainly an ambiguous cross-over between the company's gaming brands.