Never tried it myself - my Wife who has Parkinson's did it for a number of years because it really helps with balance and flexibility.

According to the Diabetes branch of the Mayo Clinic they list Tai Chi as one of the "recommended" forms of activity for Diabetics as part of an exercise program.

They note "improved balance, strength, flexibility and posture - reducing the risk of falls and decreases blood sugar levels in diabetics" (without giving specific numbers or results)

A Meta Analysis (fancy word for a study that looked at a bunch of different studies that looked at the effect of Tai Chi on A1C) showed that "compared to no exercise at all" Tai Chi resulted in a decrease of between 0.5 and 1.7% in A1C levels - and purely for "blood sugar control" it is rated as well as Aerobic Exercises (although they are more heart healthy)

So if you are looking for a low impact (exercise) and are not doing anything at the moment, the studies say it is both viable and helpful. Alternately, you can do it in your living room so a great alternative/replacement to "going for a walk outside" with a number of additional benefits (balance/posture etc) over "walking" as your regular exercise routine.

No but that sounds like a great idea!