@Doug, when can we get the 'action' attribute???!!! That would be a huge help for this issue. Everyone please vote up this idea if this an issue for you: https://sites.secure.force.com/ideaexchange/ideaView?c=09a30000000D9xt&id=08730000000H6PMAA0&mc=0

I've been able to work around this by hooking initialization into a setter method. Based on the documentation (http://www.salesforce.com/us/developer/docs/pages/Content/pages_controller_lifecycle_example.htm) for lifecycle I believe we can count on the setters for any assignTos to be evaluated prior to any getters being called.

In my example I needed to parse a sub query of an object to populate other objects. When this parsing took place in the constructor it failed as the assignTo hadn't been evaluated yet.

public with sharing class ThisWontWork {

  public Opportunity opportunityWithSubRecords { get; set; }

  public Forecast_History__c subObject1 { get; private set; }
  public Forecast_History__c subObject2 { get; private set; }

  public ThisWontWork() {
    parseSubObjects(); // <- This fails because opportunityWithSubRecords is null when the constructor is called
  }

  private void paresSubObjects() {
    for(Forecast_History__c history : cOpportunity.Forecast_Histories__r) {
      if('Type 1' == history.revenue_type__c)
        subObject1 = history;
      else if('Type 2' == history.revenue_type__c)
        subObject2 = history;
     }
  }
}

Ideally I would just call parseSubObjects from an action attribute on the component, but as that feature is not here yet I opted to use a setter side effect instead.

public with sharing class ThisWillWork {

  public Opportunity opportunityWithSubRecords {
    get {
      return opportunityWithSubRecords;
     }
     set {
       opportunityWithSubRecords = value;
       parsePriorForecastSnapshots();
     }
  }

  public Forecast_History__c subObject1 { get; private set; }
  public Forecast_History__c subObject2 { get; private set; }

  private void paresSubObjects() {
    for(Forecast_History__c history : cOpportunity.Forecast_Histories__r) {
      if('Type 1' == history.revenue_type__c)
        subObject1 = history;
      else if('Type 2' == history.revenue_type__c)
        subObject2 = history;
    }
  }

}

This has been working so far for me.