The structure in the neutral and ionized interstellar medium on AU spatial scales has been frequently observed for over three decades using several observational techniques. In the straight forward interpretation, the AU-scale 'clouds' have puzzling properties: they are highly over-dense and over-pressured, far from pressure equilibrium with the surrounding medium. Classical evaporation/condensation arguments point to a very short lifetime for such clouds, yet the AU-scale structure in the diffuse medium is quite common. Numerous new theoretical explanations were proposed in recent years trying to reconcile various observations with the ISM theory. On the other hand, recent observational progress has provided somewhat contradictory results: a lack of AU-scale structure from some experiments, while a large abundance from others. In addition, new populations of ISM clouds are emerging with properties tantalizingly similar to those of the 'classical' AU-scale clouds.

With this great diversity of observational and theoretical flavors, numerous outstanding scientific questions remain. We hope to address at least some of them during this conference. Some questions we hope to discuss at the meeting are:

• What is the current observational status on the existence and properties of AU-scale structure?
• Different observational techniques sample different types of conditions. We need to quantify these observational biases.
• Are different observing techniques converging towards consistent results?
• The classic, perhaps simplistic interpretation involves individual structures; the alternative is that the observed phenomenae are simply a result of the turbulence spectrum, with no need for individaul structures. How do we tell which is right? Are both right?
• If we have individual structures, what are their physical properties?
• If we have simply a turbulent spectrum, what are its properties (e.g. what power law)?
• At a deeper level, what astrophysical processes produce individual structures, or poduce a particular power law turbulent spectrum?
• What do the latest numerical simulations tell us about the AU scales? Do they have high enough resolution?
• Are AU-scale features in the neutral and ionized medium related?