expression
as (much as) now; as it is now
Used in comparisons, typically with a negative predicate, to mean 'not as much as now' or 'not as ... as the present situation'. Often appears as 今ほど～ない.
今ほど忙しい時期はなかった。
There has never been a time as busy as now.
今ほど彼のことが気になったことはない。
I've never been as concerned about him as I am now.
expression
Refers to the very recent past; synonymous with たった今 or さっき. Less common than sense 1 and may be considered slightly old-fashioned or literary.
今ほどお電話いただいた件ですが、確認が取れました。
Regarding the matter you called about just now, I have confirmed it.
たった今 is the standard colloquial way to say 'just now', while 今ほど in this sense is rarer and more formal/literary.
さっき is a casual word for 'a short while ago', whereas 今ほど (sense 2) is more formal and less common.
Compound of 今 (ima, 'now') and ほど (hodo, 'extent, degree'). The comparative sense developed from 'to the extent of now', while the temporal sense 'just now' is a later extension.