After seeing the first
Aside from the multimedia messaging confirmations for delivery, the new Windows Phone build now features not five, like previously in Mango, but the last eight applications recently used, which are kept in the memory. With such a multitasking limit users will be able to do more in less time (given that the memory used by apps doesn’t reach 256MB).
Additionally, build 8773 (Tango) uses memory more efficiently than 8107 (Mango), with a usage of 122MB vs. 153MB, according to reports. Check out the source link below to read more as the thread is constantly growing.
Update: Unfortunately the above reports turned out to be just partially true. The custom ROM has this feature indeed but it is not a feature of “Tango” per se. As the ROM chef himself said, it’s just a tweak he implemented.