All Visio stencil links have been moved to our main website: http://www.extremenetworks.com/support/visio-stencils
Please use the links there to download stencils for your Extreme Networks products.
If there's something you'd like to see, let us know in the comments!
EDIT (Nov. 11): Links have been updated.
EDIT (Dec. 18): Updated Summit X link to include X460-G2.
EDIT (Sept 1, 2015): Links moved to main site. Updated SummitX to include X430, X450-G2, and X670-G2. IdentiFi now includes C35 and AP3825.