We offer several LabWindows/CVI courses - formal training can be found here: http://sine.ni.com/apps/we/nioc.vp?cid=10287〈=US
For seminars, you can visit here: http://www.ni.com/seminars/ and narrow your search by product to find the LabWindows/CVI seminars.  
In general, more LabVIEW customers request training, therefore more courses are offered.  However, the number of seminars does not reflect the amount of support for a particular product.  If you would like a LabWindows/CVI training session, please contact your local field representative, or feel free to contact me directly at: shelley.gretlein@ni.com.
Thank you,
Shelley Gretlein
LabWindows/CVI Product Manager