new hosts appearing between 2012-04-20_0800 and 2012-04-21_0800:
www.energy.gov                  has IPv4 74.121.199.68 has IPv6 2605:9f00::82 (ok)
www.iij4u.or.jp                 has IPv4 210.148.162.25 has IPv6 2001:240:bb81:8500::3:101 (ok)
www.liriklaguindonesia.net      has IPv4 199.27.134.16, 199.27.135.81 has IPv6 2400:cb00:2048:1::c71b:8751 (ok), 2400:cb00:2048:1::c71b:8610 (ok)
www.nasa.gov                    has IPv4 173.223.232.138, 173.223.232.136 has IPv6 2600:809:600::3f50:41b (ok), 2600:809:600::3f50:411 (ok)
www.o2.cz                       has IPv4 160.218.161.61 has IPv6 2001:41d8:1:8f20::30 (ok)

hosts disappearing between 2012-04-20_0800 and 2012-04-21_0800:
www.census.gov                  had IPv4 148.129.75.218 had IPv6 2610:20:2110:103::1:218 
www.ecadforum.com               had IPv4 199.27.134.41, 173.245.60.116 had IPv6 2400:cb00:2048:1::c71b:8629 , 2400:cb00:2048:1::adf5:3c74 
www.kennstdueinen.de            had IPv4 80.67.27.48 had IPv6 2a00:1158:0:402:bd8a::1 
www.meo.pt                      had IPv4 83.240.175.138 had IPv6 2a02:818:2021:6240:83:240:175:138 
www.netregistry.com.au          had IPv4 202.124.247.2 had IPv6 2403:1400:2:1::101