Ask HN: Why did Google drop www.l.google.com CNAMES for standard A-records?

I noticed Google switched away from CNAME-ing www.google.com and other www.google.tld domains (such as www.google.nl) to www.l.google.com. They now serve standard A-records, which strangely enough seem to be different for the .com domain compared to all others. For example from my location, querying the authoritative nameservers (ns1 to ns4.google.com for all domains I tried):

  www.google.com.         300     IN      A       173.194.66.103
  www.google.com.         300     IN      A       173.194.66.105
  www.google.com.         300     IN      A       173.194.66.147
  www.google.com.         300     IN      A       173.194.66.104
  www.google.com.         300     IN      A       173.194.66.99
  www.google.com.         300     IN      A       173.194.66.106

While I get the same IP for several countries:

  www.google.nl.          300     IN      A       74.125.132.94

  www.google.be.          300     IN      A       74.125.132.94

  www.google.de.          300     IN      A       74.125.132.94

  www.google.co.uk.       300     IN      A       74.125.132.94

Also across continents:

  www.google.us.          300     IN      A       74.125.132.94

  www.google.com.br.      300     IN      A       74.125.132.94

And:

  www.google.jp.          300     IN      A       74.125.132.94

  www.google.hk.          300     IN      A       74.125.132.94

The single A-record returned for everything but the .com-version does change, but if it changes it changes for all TLDs at the same time and to the same new record. From another location (Germany instead of Netherlands) I observed the same thing, but with the same 3 A-records being returned each time instead of the single record as seen in the Netherlands.

Could anybody shed some more light on why they would switch from CNAME to A-records, and why the CNAME in the first place? And maybe in general more information on how their balancing/traffic-management seems to work?