Actually, that's how they're arranged already;
- the 6 Active Projects;
... Help Cure Muscular Dystrophy - Phase 2
... Help Fight Childhood Cancer
... Nutritious Rice for the World
... Help Conquer Cancer
... Human Proteome Folding - Phase 2
... FightAIDS@Home

- followed by the 4 Intermittent Projects;
... Influenza Antiviral Drug Search
... The Clean Energy Project
... Discovering Dengue Drugs - Together
... Beta Testing

- followed by the 5 Completed Projects;
... AfricanClimate@Home
... Help Cure Muscular Dystrophy
... Genome Comparison
... Help Defeat Cancer
... Human Proteome Folding

All the projects within each "sub-section", are organised in the order in which they started - thus, as HCMD2 was the last project started, it's right at the top of the "active" list, and likewise, as FA@H was the earliest project still active, it's the last in that section.

What WOULD be nice, is for a line/separator to be placed in between each group, so as to emphasise the above.

There is always a beta test before a new project launch, or if any problems are found in an existing project requiring more beta tests.

So no, beta never really goes away. It is just tough to get beta workunits if you want them, because there are not usually very many issued.