The 35-year-old's inclusion for the next month's tournament in New Zealand is the feelgood story of the Wallabies' 30-man squad and caps an incredible rise after his career looked over just 18 months ago.
After stints in France and Japan, Samo was playing club rugby in Brisbane until an injury-crisis at the Queensland Reds saw him gain a call-up from Ewen McKenzie.
He made an immediate impact and continued that form into 2011, playing a key role in the Reds' title success and gaining a Wallaby call up this season for the first time in seven years.
And it took just a 15-minute cameo in the Tri Nations Test against South Africa last weekend for Deans to rubber stamp his spot on the plane next month.
"It's a dream come true," Samo said of his surprise selection. "A lot of rugby players, even though they play Test footy they always want to play in a World Cup.
"It comes around every four years so I'm proud of myself to make the 30-man squad ...If I didn't make it then that would have been the end for me."
Samo's selection is a case of third time lucky for the hard-running number eight after he missed out on a spot in Fiji's squad in 2003, while he was not eligible for Australia for the last tournament as he was playing in Europe.
He admits he thought he would never get the opportunity to play at the World Cup when he headed to France in 2007, but the support of Deans and his family changed all that.
"When I went overseas I really thought that was it for me," Samo said. "Until last year when I came back I got a call from Robbie (Deans) that really pushed me hard for the World Cup this year.
"And all my family, my brothers and my uncle, they stuck by me and kept pushing me every week to work hard and to play hard.
"This is for them too."
Meanwhile, fellow number eight Wycliff Palu declared he will definitely be 100 percent fit for Australia's opening group game despite not playing a game for the last two months.
Palu injured his shoulder against the Highlanders on June 11 and then underwent minor knee surgery last month to put his spot in the final squad in jeopardy.
But after coming through a final fitness test on Wednesday, Deans opted to take a punt on the 36-Test forward despite knowing it is unlikely he will play a match before the opening Cup fixture against Italy on September 11.
"It (his selection) came as a surprise obviously," Palu said. "I got no indication if I was in or out, I just got told to keep training.
"I was a bit like everyone else. I was getting a bit worried because without playing many games you just rely on training and things like that.
"I wasn't expecting to get a call-up but I'm pretty happy to be in the squad and I'm looking forward to it."
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