Hamblin must now build towards the 2016 Rio Olympics. She has stepping-stones such as next year's Moscow world championships and the 2014 Glasgow Commonwealth Games in between.
The news contrasts with the October 2010 nights in Delhi when Hamblin won silver in the 800m and 1500m, becoming just the second Kiwi woman to win two individual medals on the track at the same Games. Lorraine Moller first did it in Brisbane in 1982.
The 1500m result prompted then-coach Chris Pilone to scream: "She was like Kiwi winning the 1983 Melbourne Cup", in reference to her come-from-behind blast down the home straight.
However, those 2010 times were still well behind in world terms. She was the 28th fastest woman over 800m that year; in the 1500m, she was over eight seconds off the top pace.
The former Brit, who qualified to run for New Zealand in 2009, has parted from coaches Pilone and former New Zealand representative Paul Hamblyn post-Delhi.
She is renowned for a fiery personality, incredible talent and ambitious drive.
Post-race at Delhi, coaching veteran Pilone said: "She'll clonk me because I have said she is difficult to coach but it is important not to be judgmental of her."
Hamblin half-joked in the background: "I'm just checking what he is saying."
She is believed to have wanted someone who could dedicate most of the Olympic year to focusing on her campaign. Hamblyn could not guarantee that because he also wanted to spend time with his wife and baby.
Hamblin ended up being mentored by Kyle Barnes, a PhD scholar doing his thesis on running efficiency. She has also spent time with Steve Willis in Michigan. Willis is mentoring brother Nick towards a second Olympic 1500m medal in London.
Last month, coach Barnes told the Herald on Sunday the selectors were protecting themselves on the numbers his charge was expected to meet as she recovered from injury.
"Basically, they want 'proof of fitness' and the other phrase we hear a lot is 'competitive readiness'.
"We think we fulfilled the first one at the national championships, where Nikki won quite easily; but it wasn't a competitive race."