Michael's answer is good, but informal.
Oscar-style thankyou would be entirely out of place in the IEEE conferences that I have attended.
What is the nature of the presentation? In which area?
Look for an example from last year's conference.
Some people, some cultures, are used to formal acknowledgements. Some, expect they are named correctly, with full titles.
Particularly, those who might have sponsored you, might expect some thing formal.
This work was partially funded through the X scheme from the Y.
Acknowledgements in talks, are often just the final slide. In my area, often not read out, spoken to, but brought to the attention of the audience and left on the screen during question time.
If you must orally acknowledge in your field,
"I will" - is strange. (Present tense/aspect is better)
I thank ...
I would like to thank....
I acknowledge the contributions of ....
THe acknowledgements in theses are often quite personal, but in my area, at least, in presentations and papers, usually formal.