Yes, I can't remember the exact phrasing, but I remember being a bit surprised when reading the essentials rule book on this topic.
It says that interruptions, free actions, etc can happen in any order. It also said that at the end of a turn when you are doing saving throws and status effects stop, that they also can be done in any order.
Releavant quotes from the Rules Compendium:
Other Triggered Effects: If an effect
has a trigger but is neither an
immediate action nor an opportunity
action, assume that it behaves like an
immediate reaction, waiting for its
trigger to completely resolve.
However, ignore this guideline when
the effect has to interrupt its
trigger to function. For instance, if
a triggered power alllows an
adventurer to use a free action to
reroll an attack roll, with the hope
of turning a miss into a hit, the
power must interupt the trigger ("You
miss with an attack") to function:
otherwise th attack would be resolved
as a miss.
Immediate Reactions: An immediate
reaction lets a creature act in
response to a trigger. the triggering
action or vent occurs and is
completely resolved before the
reaction takes place. An immediate
reaction waits for its trigger to
finish, not necessarily for the action
that contains the trigger to finish.
Then, within the "The Structure of A Turn" section, it lists all the things you can do at various parts of the turns... here is the relevant bits:
The Start of a Turn : Any Order: The creature can choose the order in
which things happen at the start of
its turn. For instance, if the
creature has regeneration ans is
taking ongoing damage, it can choose
to take the ongoing damage n then use
its regeneration or the other way
The Actions of a Turn: Any Order: the creature can take its
actions in any order and can skip any
The end of a turn: Any Order: The creature can choose the order in
which things happen at the end of its
turn. For instance, if the creature
has saving throws to make and is
subjected to an effect that damages it
at the end of its turn, the creature
can choose to take the damage and then
make the saving throws or the other
Then, for Free Actions it says:
Free actions take almost no time or effort. A creature can usually take as many free >actions as it wants during any turn, including other creatures turns. Examples: ....
There is an exception to this rule: A creatre can take a free action to us an attack power only once per turn. Example...
In Summary, the free action of the Wildblood speed, effectively acts as an immediate reaction, but it is only a guideline and isn't exactly the same, since its a free action. For example, which can be done before the Action which triggered it is complete, but only after the trigger itself takes place. The Mark itself, is able to be fired before the trigger even takes place if it so desires, however it does not have to, and these things can be done in any order.
As an aside... Be happy that wildblood speed is a free action and not labeled an immediate reaction, because you are only allowed to do one immediate action (interrupt, ready, or reaction) per turn.