TFS API - существует ли способ получить список переходов для типа workitem?

Угу .....

Не многим нужны переходы для WorkItemTypes.

Ну, мне это было нужно, поэтому я написал способ, как это сделать. Вот на тот случай, если кому-то это понадобится:

// Hold a list of all the transistions we have done.  This will help us not have run them again If we already have.
private static Dictionary<WorkItemType, List<Transition>> _allTransistions = new Dictionary<WorkItemType, List<Transition>>();

/// <summary>
/// Get the transitions for this <see cref="WorkItemType"/>
/// </summary>
/// <param name="workItemType"></param>
/// <returns></returns>
private static List<Transition> GetTransistions(this WorkItemType workItemType)
{
    List<Transition> currentTransistions;

    // See if this WorkItemType has already had it's transistions figured out.
    _allTransistions.TryGetValue(workItemType, out currentTransistions);
    if (currentTransistions != null)
        return currentTransistions;

    // Get this worktype type as xml
    XmlDocument workItemTypeXml = workItemType.Export(false);

    // Create a dictionary to allow us to look up the "to" state using a "from" state.
    var newTransistions = new List<Transition>();

    // get the transistions node.
    XmlNodeList transitionsList = workItemTypeXml.GetElementsByTagName("TRANSITIONS");

    // As there is only one transistions item we can just get the first
    XmlNode transitions = transitionsList[0];

    // Iterate all the transitions
    foreach (XmlNode transition in transitions)
    {
        // save off the transistion 
        newTransistions.Add(new Transition
                                {
                                    From = transition.Attributes["from"].Value,
                                    To = transition.Attributes["to"].Value
                                });

    }

    // Save off this transition so we don't do it again if it is needed.
    _allTransistions.Add(workItemType, newTransistions);

    return newTransistions;
}

public class Transition
{
    public string To { get; set; }
    public string From { get; set; }
}