CNN have totally bought into the new theory that the plane was tracked on radar into the Straits of Malacca and that it was last radar-fixed at some as yet undisclosed location roughly 100-200 miles northwest of KL.
This certainly points to one of two scenarios being more likely than others:
1. The pilot, having lost much of his guidance, was attempting to make a visual return to KL. One must then ask if moonset and local weather (something we left behind when it was assumed that the search would be much further north) played any role. METARS for relevant stations might be useful now.
2. Hostile elements, either terrorists or misguided pilot(s) were in control of the aircraft and the postulated track would suggest a terror attack planned at KL which after all has some of world's tallest buildings. One might then ask why anyone would plan such a thing especially at night (it would be approximately 0330h to 0400h local time if any terrorists managed to execute such a plan.
As either of these seem somewhat difficult to believe, we might then consider a third option, terrorist hi-jack with known landing point in Sumatra, explaining the low-altitude flight path in an attempt to evade primary radar. This even keeps alive the possibility that this plan has been successfully executed but in which case, why no announcement or demands?
Most likely outcome, but not by much, is that crippled aircraft made desperate but ultimately unsuccessful attempt to return to KL and that evidence of this will eventually be found.