"add comments to layers and then use the filtering/searching in the Timeline panel to show and hide layers according to these tags."
[update: Roland Kahlenberg adds, "The Timeline has a Label Column that allows you to group your layers. You can then select a particular group with the Select Label Group option available via right-click contextual option. Then it's a matter of Shy or Hide the selected layers."]
Also, while there is no master override Solo button in the timeline, you can also use Zorro-The Layer Tagger turn everything on to spot check a comp quick. Zorro lets you make selection and isolation sets by adding comment tags to layers, and new for CS5 is layer color label support. Here's the demo: