I've seen it work but it's not the norm.
Things I'd want to see before I thought it might be feasible:
1) Staff available with suitable skills and approach. By that I don't mean ".NET programmer", I mean detailed technical skills, business domain skills (so they understand the problem), personality fit and understand the tools and the approach (source control, methodology and so on). This can happen in large companies where there are common tools, standards and knowledge but you need to be sure that they're ticking pretty much all the boxes.
2) Tasks must be nicely divisible. The best situation is where there are whole modules, applications or tasks unstarted and you can put new people on that. It minimises upskilling, additional communication and so on. If you can't separate out what the new people will do you're likely to majorly disrupt the existing team.
3) The whole team must have bought into the approach. If the existing team don't agree that bringing people on board will be right they'll likely fight it and you're doomed.
4) You need to be sure you've addressed why it was running late in the first place. If it was just bad estimates then are you confident the new estimates are good? If it was scope creep have you got the scope and change control in hand now? If it was because the deadline moved, are you sure it won't move again?
If you can't tick all four of those off, it isn't going to work.