From looking at my logs and what I have read elsewhere, it appears that Googlebot has had an ip address change.
I received one from 64.68.82.77 today.

Here is a list of possible IPs but please fill in what I have missed
164.71.1.146
164.71.1.147
164.71.1.148
164.71.1.149
192.51.44.10
192.51.44.13
192.51.44.18
192.51.44.19
207.88.29.130
209.185.108
209.185.253
210.131.75.80
210.131.75.81
210.131.75.82
210.131.75.83
210.131.75.84
212.105.61.249
216.198.200.113
216.239.46.100
216.239.46.101
216.239.46.102
216.239.46.104
216.239.46.105
216.239.46.116
216.239.46.118
216.239.46.12
216.239.46.121
216.239.46.124
216.239.46.128
216.239.46.133
216.239.46.134
216.239.46.136
216.239.46.140
216.239.46.147
216.239.46.148
216.239.46.153
216.239.46.164
216.239.46.165
216.239.46.166
216.239.46.167
216.239.46.171
216.239.46.172
216.239.46.173
216.239.46.184
216.239.46.185
216.239.46.19
216.239.46.193
216.239.46.20
216.239.46.204
216.239.46.206
216.239.46.220
216.239.46.222
216.239.46.223
216.239.46.23
216.239.46.236
216.239.46.239
216.239.46.27
216.239.46.3
216.239.46.30
216.239.46.36
216.239.46.41
216.239.46.42
216.239.46.43
216.239.46.48
216.239.46.53
216.239.46.55
216.239.46.60
216.239.46.63
216.239.46.66
216.239.46.67
216.239.46.75
216.239.46.76
216.239.46.77
216.239.46.82
216.239.46.85
216.239.46.86
216.239.46.87
216.239.46.88
216.239.46.96
216.239.46.98
216.239.46.99
62.27.59.227
63.83.186.67
64.208.32.11
64.208.32.12
64.208.32.4
64.208.33.33
64.208.36
64.208.37
64.209.181.52
64.209.181.53
64.209.181.54
64.68.82
64.68.82.14
64.68.82.16
64.68.82.17
64.68.82.18
64.68.82.25
64.68.82.26
64.68.82.27
64.68.82.28
64.68.82.30
64.68.82.31
64.68.82.32
64.68.82.33
64.68.82.34
64.68.82.35
64.68.82.36
64.68.82.37
64.68.82.38
64.68.82.39
64.68.82.41
64.68.82.43
64.68.82.44
64.68.82.45
64.68.82.46
64.68.82.47
64.68.82.48
64.68.82.5
64.68.82.50
64.68.82.51
64.68.82.52
64.68.82.54
64.68.82.55
64.68.82.56
64.68.82.57
64.68.82.58
64.68.82.6
64.68.82.65
64.68.82.66
64.68.82.67
64.68.82.68
64.68.82.69
64.68.82.7
64.68.82.70
64.68.82.71
64.68.82.74
64.68.82.77
64.68.82.78
64.68.82.79

These were seen around the 10-11 March
crawl1.googlebot.com 216.239.46.27
crawl5.googlebot.com 216.239.46.124
crawl7.googlebot.com 216.239.46.55
crawl8.googlebot.com 216.239.46.204
crawler10.googlebot.com 64.68.82.5
crawler10.googlebot.com 64.68.82.16
crawler11.googlebot.com 64.68.82.51
crawler11.googlebot.com 64.68.82.51
crawler11.googlebot.com 64.68.82.36
crawler11.googlebot.com 64.68.82.55
crawler11.googlebot.com 64.68.82.33
crawler11.googlebot.com 64.68.82.32
crawler11.googlebot.com 64.68.82.52
crawler11.googlebot.com 64.68.82.31
crawler12.googlebot.com 64.68.82.78
crawler12.googlebot.com 64.68.82.69

I wouldn't have noticed it myself since I am too busy tracking the USER AGENT string that Googlebot uses - I'd be interested to know when and if that happens.