Differential algebraic equations (DAEs) are an important class of dynamical systems that arise in a large number of application areas (Brenan, et al., 1996). The numerical solution and analysis of general nonlinear DAEs requires the modification of traditional numerical methods as well as the development of new theory and techniques. Recent and ongoing research has developed results on the generation of stabilized completions of DAEs. This work was originally developed with an eye toward numerical simulation of DAEs. A completion of a DAE such as (1) is an ordinary differential equation (ODE) whose solutions include those of the DAE. The solutions of the completion not including those of the DAE are called the additional dynamics. Ways of converting a DAE into an ODE have been used since at least the 1970s. However, if the problem was not linear time invariant, these approaches required the problem to have explicit constraints and structure. The first general algorithms for forming completions were based on least squares solutions of the derivative array (Campbell, 1992). However, it was shown that the additional dynamics could be unstable. Recently an investigation into these additional dynamics has begun (Campbell & Kunkel, 2009; Okay, et al., 2009; Okay, et al., 2007), including showing how to modify the process of computing the completion so that the additional dynamics could have some desired stability properties. Most importantly, it was shown how stabilized completions could be computed numerically. One of the basic techniques in control theory is the design of observers, dynamical systems constructed to estimate state values for use in control laws. Since observers play an important role in control theory, it is natural to consider observers for DAEs. Work to date on observers for DAEs has primarily focused on the linear time invariant case (Blanchini, 1991; Dai, 1991; Darouach & Boutayeb, 1995; Fahmy & O'Reilly, 1989; Gao & Wang, 2006; Nikoukhah, et al., 1998) and does not easily extend to the nonlinear or time varying cases. Note, however, (Biehn, et al., 2001). Until recently, little progress has been made on the problem of designing observers for general nonlinear DAEs. After reviewing some of these new stabilization results, this talk indicates how using these ideas and algorithms will make significant progress in the problem of observer design for systems modeled by DAEs. This talk focuses on explaining and on describing approaches for solving the problem rather than on presenting specific results.