An interesting article:

http://www.nationmultimedia.com/life...-30179126.html


Yesterday afternoon on TV HRH Princess Chulabhorn (substituting for her father) presided over a ceremony to raise a 7-tiered umbrella to the top of the Meru. All of the surrounding buildings look amazing so this may be worth a visit for those currently in town.

There are a lot of press releases here, where one might be able to determine which days/times might allow for public entrance:

http://thailand.prd.go.th/list_monarchy.php

Edited to add: April 6, 7, 8 & 9, 2012 are official government/bank holidays, I didn't realize this until today. Songkhran official government/bank holidays extend from April 12 through April 17 this year.