No - It doesn't look like Googles DNS servers have been hacked.
It looks like either the IEDR (the guys who manage .ie) have been hacked, or, either Google or eMarkmonitor Inc (whoever they are) had their password for the IEDR systems compromised.
Markmonitor handles all the ccTLDs (.ie, .co.uk, .de, etc) for almost all the Fortune 500 companies. If they were hacked you'd see more than two changed .ie domains.
74.125.132.94
# dig +short @8.8.4.4 google.ie (Google DNS #2)
74.125.132.94
# dig +short @208.67.222.222 google.ie (Open DNS #1)
119.235.27.219
# dig +short @208.67.220.220 google.ie (Open DNS #2)
119.235.27.219
# dig +short @ns1.farahatz.net google.ie
;; connection timed out; no servers could be reached
# dig +short @ns2.farahatz.net google.ie
;; connection timed out; no servers could be reached
# whois 74.125.132.94
...
NetName: GOOGLE
...
# whois 119.235.27.219
...
netname: LINTASLINK-ID
...