This is a pathetically inaccurate legal answer, but it should fit your purpose of getting an idea of the legal ramifications involved and suggesting some reasons as to why the sentence was so low.
Firstly, he violates parole in New York. According to the New York State Department of Corrections and Community Supervision:
What happens when an offender violates his parole?
When a parole officer determines that an individual released to parole
supervision may have violated the conditions of release, either by
committing a new crime or failing to adhere to the conditions of
release, the Parole Board's regulations provide for the issuing of a
detainer warrant. If a warrant is issued, the releasee will be
arrested and detained in a local jail awaiting the outcome of a parole
If the charges alleging a violation of parole are not sustained at the
violation hearing, the warrant will be lifted and the releasee
restored to supervision. If the violation charges are sustained, the
releasee may be ordered returned to state prison for a duration of
time to be determined by the Board of Parole, or referred to an
alternative treatment facility - such as the Willard Drug Treatment
So it's likely he would have had a hearing and a possible prison sentence based on this violation.
He also causes criminal damage (in Nebraska I think). The link to the Nebraska state legislature wasn't working, but I took a look at Michigan laws instead, to get a rough idea:
Felony Willful & Malicious Destruction Laws
If any of the following apply to your case, you will face felony
charges and a potential maximum sentence of up to 10 years in prison
and fines of up to $15,000 or three times the value of the damage,
whichever is greater.
- The value of damage is greater than $20,000, or
- You have 2 or more
prior convictions of malicious destruction.
You could face felony
charges and up to 5 years in prison and fines reaching $10,000 or
three times the value of the property damage, whichever is greater if
any of the following apply to your offense:
- The value of damage is between $1,000 and $20,000, or
- You have one or
more prior convictions of this offense.
So that's a rough indication as to the types of penal sentences possible.
WiseGeek did a brief article on sanctions for illegal street racing, which included a possibility of jail time for repeat offenders (as opposed to just impounding and fines for first timers).
As for the possible injury/death to police officers - as this is offscreen, we never see it or know much about it. I think for the purposes of the movie, and to promote Aaron Paul as the "goodie", we are expected to assume there was no serious injury. Unfortunately, this is a common trend in movies/tv series (think things like The Dark Knight, with Batman flipping police cars).
Ultimately, even assuming no major injury to officers, it appears there's a fair few sanctions he was facing and his jail sentence seems unduly lenient. So now on to the important question!
Why is his prison sentence lenient?
He's the anti-hero. He's not a typical, breathtaking goody, but he's the guy we're meant to care about and thus he gets a happy ending. He gets put away, which shows the film-makers didn't just "forget" about his crimes, but they reduced the penal sentence to suggest he could get out at the end and live his life normally again. This is not that uncommon, e.g. Snake Eyes for example.
This was discussed over at the IMDB thread for the movie, with someone suggesting "it's possible the real evidence of Dino being guilty could have helped him since he got 2 years for something he wasn't responsible for to begin with."
It could be argued it is a nod to the Need for Speed game series, where drivers frequently get busted by police with no real consequence.
Obviously, the most boring explanation but - it's a movie. Think of the endings to films like The Fast and the Furious and Gone in 60 Seconds. It all lets the good guy come out on top due to his "righteous" cause.
As stated at the start, the law presented here is very rough, but hopefully it provides some basis for your answer.