Until Apple introduces iOS notification system, in the meantime, you can customize the look and feel of iOS notification alert using "AlertArtist," a tweak for jailbroken devices available on the Cydia store.
The program lets you customize a number of elements, such as typeface and the color of border, font and shadow. Or, you can quickly switch between one of the pre-installed templates. If you've been on the lookout for the ultimate multitasking tweak for your jailbroken device, look no further than Physwitch.
Physwitch, another handy Cydia tweak seen in the below video, lets you easily switch between running apps by hitting the volume up and down keys. You can set the app to activate, say, when you hit both buttons simultaneously. This lets you use the volume keys to both multitask and control the volume.